Category Archives: teaching

The Things I Teach

“OK, today in focus we’re going to read  Grandfather’s Journey together. We will find new words on each page, talk about vocabulary and meaning.”


“Me! I know!” Marshall waved his hands. “It is….the father of your father.”

“Also the father of your mother, right?” Charlotte asked.

“Abuelo?” Kit looked to Marshall.

“Yes, abuelo,” I nodded. “But what about journey?”


“I think it means hat,” offered Julian.

“Sombrero?” Kit was surprised.

“No,” I shook my head. “Journey means ‘trip’. It means…to travel. To go somewhere else.” Blank looks. I grabbed a white board and drew–badly–what I call in my history classes the Great American Porkchop with an airplane, also rendered poorly.


“Ahhh!!” Comprehension. They didn’t laugh. So don’t you mock my artwork.

Charlotte said, “So I took a….journey from the Congo?”

“I took a journey to India?” asked Amit.

“No. From.”

I pointed to “Here” on my sketch. “In a journey, your beginning point is from. Your end point is to.”

“So I came from China to America?” asked John.

“Use journey.”

“OK. I took a journey from China to here.”


“I…journey from Mexico to America.”

took a journey,” said Charlotte.

“Either. I journeyed from Mexico to America is good, or I took, or I made, a journey” is good. Kit?”

“I….took journey from Mexico to America.”

“Good! Sebastian.”

Long pause.

“Sebastian, put the phone away or you’ll lose it.”

“I journey from China to…here.”

Fun, clear learning, but five minutes had gotten me through two words.

“My grandfather was a young man when he left his home in Japan and went to see the world. He wore European clothes for the first time and began his journey on a steamship.”

“Look at the difference between Grandfather in the first picture and then on the steamship.”

“He is not wearing…same clothes.” from Amit.

“Oh! He is dressed like he is from Japan!” said Julian, “and now he is dressed like an American. Why is that European?”

“So does everyone see what Julian means? He is dressed in what we call traditional clothes. This story is about the past, yes? About a long ago time?” Nods. “Well, in this long ago time, Europe was more well-known than America. Today, Julian thinks of America before Europe. Today, probably the best word to use for this sort of difference is ‘Western’. Why would he want to dress in different clothes, Kit?”

Kit is quiet, particularly compared to Marshall, whose American aunt is really helping him develop skills. He paused. “He…belong?”

“He won’t be strange,” offered Charlotte.

“Yes, he wants to fit in, or assimilate. Good! Back to the book. The Pacific Ocean surrounded him.

“Océano Pacífico!” Marshall beamed. “That’s here.”

“Yes, and now we know the first part of his journey,” I walk over to the large wall map. “He left from Japan” (points) “and traveled across the Pacific Ocean. Where will he end up?”

“AMERICA!” chorused from all six.

“What does surround mean? Sebastian?” Sebastian tried to check with Julian in Chinese, but I stopped him. “He is on a boat, yes? In the Pacific Ocean? What would he see?”


“Amit, would he see land?” Amit was puzzled. I went back to the map, showing the trip. “He would be here. Would he see land?’

“No. Only water.”

“Yes. Surround means that everywhere you look, you see only one thing. It could be water. It could be people.”

“So what does ‘surround’ mean, Kit?”


“All around.” Sebastian.

For three weeks he did not see land. When land finally appeared, it was the New World.


“Kit, we just talked about days of the week. How many days in the week?”

“Seven,” jumped in Amit.

“Is that right, Kit?” Kit nodded. “So if the grandfather traveled for three weeks, and each week is seven days–and this is only for Kit–how many days did he travel?”

Kit clearly knew the answer, but needed time to put it in English. I held back everyone else with my hand, giving him time. “Vienti…no. Twenty. Twenty one.”

“Twenty one days on a boat?” Charlotte was skeptical.

“It was a steamship, which would be faster than sailing.” I googled up an image on my cell phone and held it up and walked around to give kids a look.

“Oh, so he didn’t fly on a plane,” Julian. “Twenty one days is a long time.”

“Yes. We can travel more quickly these days. That changes everything. Think about how different you would feel if you had to travel for twenty one days.”

“Please–I would travel more, yes?”

“Longer, not more. Yes, it is a longer journey from India.”

Sebastian was puzzling over the second sentence. “What is New World?”

“America,” Marshall offered.

“Yes, all America. North and South. Mexico is part of the New World. So is Canada.” Back to the map. “All of this.”


He explored North America by train and riverboat and often walked for days on end. So a riverboat is a boat that travels on a river, yes? Who can tell me what a river is? Kit?”


“Yes. Like the Mississippi, here on the map. It’s a…long.. you know? It’s long, but much skinnier than an ocean. Also, ocean is salt water. Rivers are in countries and are not salty.”

“Rio Grande!” from Marshall.

Amit looked confused. I googled “Punjab rivers” and then brought up an image of the Chenab to show him.”

“Oh! Yes. Rivers. Big. Punjab has many rivers. Five.”

“Charlotte is from Africa, which has the Nile,” said Julian.

Charlotte snorted. “The Nile is in Egypt. We have the Congo River.”


“What does explore mean?”

“Aagh!” Marshall smacked his head. “No sé cómo decirlo en Inglés (at least, that’s what Google says he said.) Uh, he looks at. No. Looks…deep.”

“Explore means to learn about…to study. No…is that it?” said Charlotte.

“Yes, Marshall and Charlotte have it right. Explore means to learn about a new place, a new idea–or maybe something you already know a little bit about. Marshall says ‘deep’, to go deep into a subject. Good work! Now, think about that with journey.”

Julian said, “So you go on a journey to explore.”

“Outstanding. Let’s put it in the story terms. We are reading a story about the author’s grandfather, who has crossed the….”

“Pacific Ocean” they chorused.


“explore America!”

“Good! Deserts with rocks like enormous sculptures amazed him.”


“What is ‘amazed’?” asked Charlotte.


“I don’t know. What is a sculpture?”

“it’s art formed out of a hard material–rock, or metal.” I googled “rock formations America” and held up the results one by one. To a kid, they all gasped in…

“Yes. You see that feeling? That is amazed. See how you are all thinking oh, how beautiful. How you didn’t know about such beauty. It’s when you see something good…or bad..or just different. But something you didn’t expect. So when you came to America, what amazed you?”

“The food,” offered Charlotte instantly. “I was..amazed at how much food. How much you could much you could have. It is wonderful.”

“I was amazed that you can take cellphones to class. But mostly that you can ride bikes on the road, with cars,” from Julian.

I chuckled. “Yeah, that’s a quick way to die in China, huh?”

“Here the cars have to stop!”

“See Julian’s behavior, guys? He is acting amazed. Sebastian, what amazed you about America?” Sebastian clearly understood the question, but said something in Chinese to Julian.

“Oh, that’s true,” Julian turned to me. “He said..oxygen. You can’t see it here.”

“The air! Yes, the air in America is so much cleaner, so much clearer, is that it?” Sebastian nodded. “So can you put that in a sentence?”

“I was amazed at the clean air in America.”

“Good! Back to the book. The endless farm fields reminded him of the ocean he crossed. Endless? Kit?”

“No stop?”

“Keeps on going.” said Marshall. “But what is field?”

“A field is an open space, a big one. A farm field is an open space used to grow food.” I googled corn fields and wheat fields .  We determined that the grandfather was seeing wheat fields in this picture.

“So the author is making a comparison. Just as he traveled across the Pacific for twenty-one days, surrounded on all sides by water, so too did these fields seem to go on forever.”

“Like an ocean,” said Max.

“Yes. See how the author drew the fields to look like an ocean, surrounding the grandfather? Huge cities of factories and tall buildings bewildered and excited him.


“Who can tell me what bewildered means?”

Amit, galvanized, pulled out his phone, looked at me for permission. I nodded, and he handed me the results.

“Oh, perfect!”

“Ah!” the class chorused. They all got it at once.

“So bewilder means to confuse you, to see or experience something that fills you with questions. Nice job, Amit.”

“I…feel bewildered a lot.” Amit replied, and everyone nodded.

“Welcome to America!” laughed Chancelle.

He marveled at the towering mountains and rivers as clear as the sky.


“But ‘tower’ is like a building,” puzzled John.

“Maybe the mountains are big, like tower,” offered Max.

“Yes, that’s it. Like a tower. He’s comparing the mountains to a tower, like this.” and I googled some towering buildings. “See? What does marveled mean?

Kit muttered something.

“What? Could you say it again?”


“Ah, yes, like…” Max, like me, uses his hands to fill in blank spaces.

“Would you say marvelous is like amazed?”

“Yes!” Charlotte beamed. “They mean the same thing!”

“Close to it. So notice, let’s page back. The author said his grandfather is amazed, excited, and that he marveled. All of these words have similar meanings. So the author is creating…making a mental image for you.”

“The grandfather is seeing many things that surprise him but…they are good things,” Julian nodded.

“Please–the words mean the same?”

“Not every word, Amit–but amazed…do you see, go back? Amazed and now to the cities page. Excited and now the mountains page…marveled. Everyone see those words? They all have very similar…very close meanings.”

“But not ‘bewildered’.”

“Good! Bewildered is something different. That’s why the author writes yet .See that small word? Yet means that he was confused but still feeling…”

“He is confused but happy he is seeing all this.”

“Exactly! Going on: He met many people along the way. He shook hands with white men and black men, with yellow men and red men. In Japan, would he have seen only other Japanese people. Julian, Sebastian, did you see people who weren’t Chinese before you came to America?”

“No,” Sebastian shook his head. “Only…movies.”

“Only in movies. Charlotte, Congo is mostly black people, but there are some white people there, too, right?”

“Yes, also Chinese. Not…many. But some Chinese.”

“Chinese people in Africa?” John couldn’t believe it.

“Yes, Chinese people are starting to build businesses in Africa.  Asia and Africa are less diverse–they are mostly one race. Well, not North Africa.”

“Yeah,” Charlotte nodded emphatically. “Egypt, Libya, they… have more types. More races. More…mix.”

“Mexico, too,” said Max, and Kit nodded.

“Yes. North and South America have had more than one race for many years–because we’re the New World. Many people from different places came here. Mostly white in North America at first, but still blacks and Hispanics, and even some Asians. But Asia, particularly East Asia, doesn’t see many differences.”

“India has many types,” said Amit.

And the bell rang. Nine pages.

Debrief and other thoughts soon.

Great Moments In Teaching: The Third Dimension (part II)

In our last episode, the class was engaged in sense-making, thinking aloud, arguing aloud, just plain being loud, at the math behind this sketch:

“So up to now we’ve spent a lot of time in the coordinate plane thinking about lines. In the two-dimensional plane, x is an input and y is an output. A line can be formed by any two points on the coordinate plane. We’ve been working with systems of equations, which you think of as algebraic representations of the intersections of two lines. We can also define distance in the coordinate plane, using the Pythagorean theorem. All in two dimensions. So now we’re seeing how this plays out in three dimensions.”

I drew another point, showing them how the prisms were formed, how you could see a negative or positive value:


More students began to see how it worked, as I’d call on a kid at random to take me to the next step. When I finished a second point, the chaos was manageable, but still loud.

“Yo, you want me to be honest with you?” Dwayne shouted over everyone.

NO!” I bellowed. “I want you to be QUIET!” Dwayne subsided, a little hurt, as I go on, “Look, this is a great discussion! I love watching you all argue about whether or not I’m making sense. But let’s stay on point! I got Wendy questioning whether or not I know what I’m doing, Dwayne howling every time he loses attention for a nanosecond….”

Teddy jumped in.

“Here’s what I don’t understand. How come you have to draw that whole diagram? We don’t have to do that with the usual graph….in, what, two dimensions? So why do we have to do it with three-D?”

“Great question. Here’s why. Go back to my classroom representation. According to this, the Promethean is a quarter inch from Josh, Hillary and Talika in the front row. Was anyone thinking that I’d drawn it wrong?”

“I learned this in art!” Pam, also up front and up to now watching silently, said, while comments around nearly drowned her out. I hushed everyone and told her to say it again. “It’s like…we need to draw it in a way to make our brains see it right.”

“That’s it.”

“My brain hurts to much to see anything!” Dwayne moaned.

“But we don’t have to do it with, you know, x-y points.” Natasha.

“Good! Let’s go back to two dimensions. If I want to plot the point (2,3), I’m actually plotting the lines x=2 and y=3, like this:

Alex said “Oh, hey. There’s a rectangle. I never saw that before.”

“You never seen a rectangle before?” Dylan. I ignored him.

“Right. The point is actually the intersection of the two lines, forming a rectangle with the origin.”

Alex again: “Just like this one makes a cube…”


“a prism with the intersection of the three points. But how come you have to draw it? I don’t have to draw a rectangle every time I plot a point.”

“But three dimensions make a single point much more ambiguous.”

Dwayne sighed loudly and held his head. “This ain’t English class. I can’t handle the words.”

“Ambiguous–unclear, able to be interpreted multiple ways. Let’s start with this point:


“What are the coordinates of this point?”

“Easy,” said Wendell. “Just count along the lines.”

“Okay. How about (-1, -1, 2)?” I count along the axes to that point.


“How about (8, -10, 11)?

“They can’t be both!” protested Wendy.

“How about (2, -4, 5)?”

While I listed these points, I followed along the axes, just as Wendell suggested.

“How can you have three different descriptions of one point?” Josh asked.


“But that means there would be three different cubes…prisms?” Manuel.

“Yep. Let’s draw them.”

Something between controlled chaos and pandemonium dominanted as I drew–with class participation–three paths to that point, and the cubes. With each point, I could see again that increasing numbers were figuring out the process–start with the intercepts, create the two-dimensional planes, join up the planes.

When all three were finished, I put them on screen one after the other.

Sophie, ever the skeptic, “Those can’t be the same point.”

Wendy: “I’ve been saying that.”

Arthur stood up. “No, you can see!” He came over to the Promethean and I gave him the pen. “Look. Here’s the original. Start at the origin, go two to the left, and one up. Each one of the pictures” and he shows it “you get to the point that way. So the point is the same on all the pictures.”

Sophie was convinced.

Dylan: “So how come it’s not just (-2, 1)?”

Arthur looked at me. “It’s not (-2,1) but it is (-2, 0, 1).” I replied.

“Oh, I see it!” Wendell came up. “See, you go along the x as negative 2. Then you don’t go along the y. Then you go up 1 on z?”

“You got it.”

“Can you do it for x and y, without z?” Josh.

“Take a look. Let’s see.” And with many shouts and much pandemonium, the class decided that the point could be plotted as (-3,1,0) or (-3,1) on the two dimensional plane.

“Whoa, there’s lots of possible ways to get to the same point.”

“Can you figure out a way to count how many different ways there are to plot the point?” asked Manuel.

“That’s a great question, and I don’t know the answer. My gut says yes, but it’d be a matter of combinatorics. Outside the scope of this class.”

“Thank god,” said Wendy, and I shot her a look.

In other classes, I let them work independently on the handout at this point, but 4th block is crazy loud and easily distracted, so I brought them back “up front” to check their progress every 10 minutes. The whole time I was thinking, man, I’ve controlled the chaos and the skeptics this far, do I dare do the last step? Or should I keep it for tomorrow?

Here’s where the performance aspect kicked in: I wanted a Big Close. I wanted to bring it all together. Even if the risk was losing the class, losing the tenuous sense of understanding that the weaker kids had.

I wanted the win. After they’d all sketched three prisms, I started up again.

“I began this lesson with a reminder of two dimensional planes. The only thing we have left is distance.”


“How do you find the distance of a prism?” said Francisco.

“What would the distance be?”

I drew a prism:


“Oh, okay,” said Sanjana. “So the distance would be to the corners.”

“Yeah, the lower left is the origin, right? And the top right is the point,” said Sophie.


“Now, you learned this formula in geometry. Anyone remember?” I look around, and sigh. “Really, geometry is a wasted year. Does anyone see the right triangle that the distance is the hypotenuse to?”

Dwayne sighed. “God, Hypotenuse! I don’t…”

“HUSH. Tanya?”

Tanya frowned. “Would one of the legs be the….the height?”

“But where’s the other leg?” asked Jenny. “It can’t be the length or the width.”

“No. It’s across the middle,” and I drew the second hypotenuse and labeled everything.


“So now you can see that the x coordinate is the length, the y is the width, and z is the height. I just labeled the other distance w. So how do I find a hypotenuse length?”

Relative silence. I growled.

“Come on, it’s the mother ship of geometry. In fact, I mentioned it earlier.”

Still silence.

“Keerist. You all bring shame to your families.”

“Wait, do you mean the…the thing. a squared plus b squared?”

“The thing?”

“Pythagorean theorem!” half the class chorused.

“Oh, NOW you know it. So how can I use that here?”

“x2 plus y2 equals w2,” offered Patty.

“Yes, and the other one would be “w2 plus z2 is distance, squared,” said Dylan, who’d decided he couldn’t disrupt class, so he may as well participate.

“Great. We have two equations, right? Kind of like a system.”

“But there’s way too many variables. We only have two, right?” Sophie frowned.

“Great question again. To solve a system, we need as many equations as we have variables. But since we aren’t using any specific values at all in this discussion, we aren’t looking for a full solution.”


“So what are we looking for?”

“The EXIT!” shouted Dwayne.

I howled back, “Exit is in 15 minutes. BE QUIET!–Again, a good question. What we do in math sometimes is look for meaningful algorithms that can be formalized into useful tools. Like in this case. Right now, I’d need to go through several steps in order to find the distance of a prism. I want it to be simpler. How can I simplify or restate a system? Natasha?”

Natasha, tentatively, “We can add them up.”

“OK, like combination. Anything else? (SHUT UP DWAYNE!) Natasha? No? Fine. Dwayne?”

“Who, me? I don’t know anything!”

“Bull crap. I scrawled on a new page:

2x + y = 14

“What do you do?”

“Wait. You mean where you…oh, ok, you put the 3y in for the x and then multiply by 2.”

“Try not to be shocked by your own comprehension. That’s correct.”

“Yes,” Dylan said. “You can substitute. How come you never have a substitute?”

“Excluding his extraneous crap, Dylan has also stumbled onto truth. Substitution. And looking at the equation, I see an opportunity. An isolated opportunity, even. We have two variables that aren’t length, width, and height, right?”

“Yeah. w and distance,” Alex offered. “But we’re trying to find the distance.”

“Exactly. What I’d like to get rid of, really, is that pesky w. And oh. Hey.”

I drew a circle around x2 plus y2 and pointed it at w2 in the second equation


Manuel got it first. “Holy SH**!”

Teddy, Alex, and Sophie were right behind him verbally, although Prabh and Sanjana had already figured it out and were rapidly taking notes, working ahead of me.

As I wrote down the final equation, they were shouting it along, and eventually all the class joined in: “X2 PLUS Y2 PLUS Z2 = DISTANCE SQUARED!” and as I finished it up, hand to god about a third of the class clapped madly (while the rest looked on in bemusement).

I bowed. I don’t, usually.

“But where’d the w go?” asked Josh in bewilderment.

“That’s the point, the system substitutes x and y so you only have to use the length and width and height!” shouted Manuel.

“So you never have to find w!” added Sophie.


“Pretty cool, huh?”

And the bell rang.

How to explain the adrenaline rush all this gave me? It took me a good hour to return to earth. They clapped! Not all of them, but so what?

So much of my time is spent slowing down math to be sure everyone gets it. I rarely can really engage and challenge the top kids “up front”. I give them challenges at other times, and they usually like my lectures, but I don’t often have the opportunity teach something in a way that makes sense to the less advanced but still captures intellects at the high end.

Here, it happened. The top kids understood that I’d piece by piece revealed that 3-dimensions are just an extension of the two dimensional system they all knew, but had never thought of that way. Not only did I reveal it, but I did so while using systems, something they’d just been working with. They were admiring the artistry. They got it.

And I did it all with Dwayne and Dylan yipping at my heels.


(Here’s an actual promethean shot from that day. The rest of them I rebuilt.)


Not Negatives–Subtraction

In summer school, I’m teaching what used to be known as pre-algebra and happily, my colleagues had a whole bunch of worksheets that I got on a data stick. Very nice, and the curriculum was very good, leaving me time to tweak but not spend all my time inventing.

It’s not like the curriculum was a surprise: integer operations and fractions played a big part.

Of course, when we math teachers say “integer operations”, we mean “operations with negative integers” because while we don’t really care all that much if they’ve memorized their plus nines and times sevens (sorry, Tom!), kids that don’t fundamentally understand the process of addition are usually un-included by high school.

But negative numbers are one of those “Christ, they’ll never get it” topics. I don’t reliably have an entire class of kids who answer 9-11 with -2 until pre-calculus. I’m not kidding. They say 2, of course. But not negative 2. And if you give them -3-9, they will decide it’s 12 or -6 or, god forbid, 6. But not -12. They’re actually not terrible at subtracting negatives, provided that it’s subtracted from a positive. So they know 9-(-12) is 21, but have no idea what -9-(-12) is, and wildly guess -21.

I’ve suddenly realized that negative numbers aren’t really the problem. Subtraction causes the disconnect, as a result of the tremendous bait and switch we pull when moving from basic math to the abstractions needed for advanced math.

In elementary school, kids learn addition and subtraction. They are not told that they are learning addition and subtraction of positive integers. Nor are they told that they are only learning subtraction when the subtrahend is less than the minuend and, by the way, we need new terms. Those are horrible. In fact, kids are told that they can’t subtract in these cases.

At no point are kids told that everything they’ve been taught is temporary, and that much of it will become irrelevant if they move into advanced math. Consider the big fuss over Common Core subtraction, which is all about an operation that has next to no meaning in advanced math other than grab your calculator. (No, this isn’t an argument pro or con calculators, put your hackles down.) Or consider the ongoing drama over the aforementioned “math facts memorization” which, frankly, gets turned ass over tincups with negatives and subtraction.

Common Core requires that sixth grade math introduce negatives. Along with ratios, rates, fraction operations, and statistical analysis, all tremendously complicated concepts. In seventh grade, things get serious:


Never mind that most non-mathies would clutch their pearls at the very thought of parsing these demands, or that these comprise one of nearly twenty standards that have to be covered in seventh grade. Leave that aside.

Focus solely on NSA1B and NSA1C which, stripped of the verbiage, define the way we math teachers reveal the bait and switch.

So first, you teach the kids about these negative numbers and how they work. Then you show them that okay, we kind of lied before when we taught you that addition always increases. Actually, the direction depends on whether the added value is positive or negative.

But that’s it! That’s all you have to know! Just this one little thing. So negative numbers allow us to move in both directions on the number line.

And subtraction? Piffle. Because it turns out that (all together now!) Subtraction is addition of the opposite. Repeat it. Embrace it. Know it. Then everything makes sense.

So we teach them these two things. Yeah, we lied about adding because we had to wait to introduce negative numbers. But there’s this one little change. That’s all you have to know! because subtraction is a non-issue. Just turn subtraction into addition and funnel it all through the same eye of the same needle. Dust your hands. Done, baby.

Well, not done. As I said, we all know that negative numbers are brutal. We build worksheets. We support the confusion. We do what we can to strengthen the understanding.

But over the years, as I started teaching more advanced math, I realized that subtraction doesn’t go away. Subtraction is essential. It’s the foundation of distance, for starters.

And what the standards don’t mention is that introducing negative numbers changes subtraction beyond all recognition. The people who “get” it are those who reorder the integer universe spatially. Everyone else just stumbles along.

Until this summer, I never addressed this issue. I’m pretty sure most math teachers don’t, but I welcome feedback.

How do we change subtraction?

For starters, we violate the rule they’ve been taught since kindergarten. Turns out you can subtract a bigger number from a smaller number. (And, when a kid asks, “Well, in that case, how come we have to borrow in subtraction?” we teachers say…..what, exactly?)

But that’s just for starters. Take a look at the integer operations, broken down by sum and difference. (Much time is spent on teaching students “sum” and “difference”. More on that in a minute.)


So first, a row of numbers like this brings home an important fact: the Commutative Property ain’t just for mathbooks. This provides a great opportunity to show students the relevance of seemingly abstract theory to the real world of math.

But notice how much simpler the addition side is. I color-coded the results to show how discombobulated the subtraction pairs are:


Middle school math teachers spend much time on words like sum and difference, but I’m not entirely sure it helps.

For example, consider the “difference” between -9 and -5, which is -4. First, -5 is greater than -9, a complicated concept to begin with–and -4 is greater than both. And–even more confusing to kids taught to limit subtraction–none of those relationships matter to the result.

So -9 – (-5) = -4. Which is the same as adding a positive 5 to -9. So the difference of -9 and -5 is the same as the sum of -9 and 5.

Meanwhile, -9 – (-5) is subtraction of a negative, which we have hardwired kids to think of as “adding”–which it is, of course, but adding in negative-land is subtracting. So what we have to do is first get kids to change it to addition, then realize that in this case, the addition is a difference.

It’s not illogical, if you follow the rules and don’t think too much. But “follow the rules and don’t think too much” works for little kid math. As we move into algebra, not so much–we discourage zombies. Math teachers are always asking students, “Does your answer make sense?” and how can a student answer if subtraction makes no sense?

One of the things I’m wondering about is the end result of the operation. Any two numbers have a difference and a sum, all expressed in absolute values. 9 and 5 have a difference of 4 and a sum of 14, and no matter what combination of sign and operation used, the answer is the positive or negative of one of these two. So I ordered them by the end result.


Notice that P+P, N+N, P-N, N-P are ultimately collective sums. No matter the relative size, P+P and P-N move to the right, N+N, N-P move to the left, and result in a positive or negative sum of the two terms.

That looks promising, but I’m not sure how to work with it yet, particularly given the confusion of the actual meanings of sum and difference.

Here’s what I’ve got so far, and how I’m teaching it:

  1. What students think of as “normal” subtraction is actually “subtraction of a positive number”, where the subtracted number is smaller. Subtraction of a positive number always involves a move to the left on the numberline.
  2. In subtraction, the starting value does not change the direction of the operation–that is, -9 – 5 and 9 – 5 will both go to the left.
  3. The starting value must not change. This is a big deal. Kids see -9-5 and think oh, this is subtracting a negative so they change the -9 to 9. No. It’s subtracting a positive.
  4. Please, please PLEASE sketch it out on a numberline. Please? Pretty please?

Hey, it’s a start. I also use a handout I built six years ago, during my All Algebra All The Time year (pause for flashback) and has proved surprisingly useful, particularly this part:

I am constantly reminding kids that subtraction is complicated, that the rules changed dramatically. Confusion is normal and expected. Take your time. I am seeing “success”, with “success” defined as more right answers, less random guessing, more consistent mistakes in conception that can be addressed one by one.

I don’t know enough about elementary and middle school math to argue for change, except to observe that much more time is needed than is given. I once took a professional development class in which a math professor covered an abstruse explanation of negatives and finished up by saying “See? Explain it logically and beautifully. They’ll never forget it again.” We laughed! Such a kneeslapper, that guy.

But I’m excited to get a better sense of why kids struggle with this. It’s not the negatives. It’s subtraction.

Great Moments in Teaching: When Worlds Collide

I’m on vacation! I actually took a whole half day off to add to my spring break, spent a couple days with my grandkids (keep saying the phrase, it will get more real in a decade or three), then embarked on an epic road trip through the northwest. My goal to write more posts is much on my mind–despite my pledge, I’ve only written 10 posts this year. But I’ve gotten better at chunking–in years past, I would have written one “teaching oddness” post, rather than three.

So this new semester, new year, has already seen some teaching moments that are best thought of as crack cocaine, a hit of adrenaline that explodes in the psyche in that moment and every subsequent memory of it, the moments you know that all those feel-good movies about teaching aren’t a complete lie. Not all moments are big; this one would barely be noticed by an outsider.

I was explaining slope to one of my three huge algebra 2 classes, the most boisterous of them. Algebra 2 is tough when half your kids don’t remember or never learned Algebra 1, while the rest think they know all there is to know, which is y=mx+b and the quadratic formula (no understanding of what it means or how to factor). Meanwhile, my recent adventures in tutoring calculus (be sure to check out Ben Orlin’s comment) has increased my determination to improve conceptual understanding among my stronger students, even if my weaker ones get a tad bored.

“I want you to stop just thinking of slope as a number, something you can only get by looking at two points, subtracting y1 from y2, then x1 from x2. The simplest way to start this process is to consider the slope triangle, which I know a lot of you use to find the slope, but don’t really think about.”

“But think of slope as represented by an actual right triangle. The legs represent the relative change rates of the horizontal and vertical (the x and the y). The hypotenuse is the slope. You can see the rate of change. It’s not just a number. Evaluate slopes by their triangles and you can see the ratio in action.”

I’m skipping over some discussion, some give and take. As I drew pictures, I “activated prior knowledge“, elicited responses as to what slope was, what the slope-intercept form represented, etc. But this was pretty close to pure lecture. I can read the audience–they’re not hanging on every word, but they get it, I’m not preaching to snoozers.

“How many of you remember right triangle trigonometry last year, in geometry?” A few hands, mostly my top kids.

“Come on, SOHCATOA?”

“Oh, yeah, that stuff” and most hands go up.

“So when I teach right triangle trig, I do my best to beat into your heads that the trig identities are ratios. Trigonometry is, in fact, the study of the relationship between the ratios of triangle legs and the triangle’s angles.”

“And that means you can think of the slope of a line in terms of its trigonometric ratio. Take a look at the triangle again, but now use your geometry lens instead of algebra.”


“The slope of a line is rise over run in algebra. But in geometry, it’s opposite over adjacent. The slope of a line is identical to the slope triangle’s tangent ratio.”

“Holy SHIT.” Every head turned around to the back of the room (where the top kids sit), where Manuel, a big, rumpled, exceptionally bright sophomore was staring at my board work.

I smiled. Walked all the way to the back of the room, to Manuel’s desk, tapped it lightly. “Thanks. That means a lot.” Walked back all the way to the front.

Remy smiled knowingly. “That was like some sort of smart-people’s joke, right?”

“Naw,” I said. “His worlds just collided.”

I could do a bit more, explain how I followed up, but no. You either get why it’s great, or you don’t.

<mic drop>

Handling Teacher Preps

I was initially horrified at my schedule when I first saw it last June. Having since conceded the possibility–just the possibility, mind you–that I might have overreacted, I thought I’d discuss teacher preps.

Preps is a flexible word. A teacher’s “prep period” describes the free period the teacher gets during the day, ostensibly to “prep”are. “I’ll do that during my prep” or “I go get coffee during “prep”. But if a teacher asks “How many preps do you have?”, the query involves the number of separate courses the teacher is responsible for. So a teacher could say “I have no prep, but I’m only teaching one prep–geometry” or “I’ve got three preps and it’s brutal” without explaining which prep is which.

Non-teachers can’t really understand preps properly without realizing something I’ve mentioned frequently: teachers, particularly high school teachers, develop their own curriculum.

Odd that I’m mentioning Grant Wiggins again, but a little over a year ago, he said that too many teachers are “marching page by page through a textbook”. I’m sure that’s true, but said even teachers who march through a textbook using nothing but publisher generated material, make decisions about which problems to work, which test questions to use, and, unless they are literally walking through the textbook as is, which sections to cover. And those are extreme cases. Most teachers that I would describe as “textbook users” still make considerable decisions about their curriculum, including going “off-book”.

So preps are a proxy for workload. A teacher with four preps has a much greater workload than a teacher with one prep.

I’ve taught at 4 high schools (including my student teaching) and observed how many others operate. So this next description is typical of many schools, but variations on the theme occur.

At both the middle and high school level, math teachers are kind of like the swimmers in Olympic sports—we’ve got the most events.

English has many courses, but more of them are electives (journalism, creative writing) and then there’s the “ELL” split that few teachers cross. Most students take a four year sequence by grade, either honors, AP, or regular. Science and history courses add up because unlike math, each course has an AP version. Science has a 3-year sequence that lower ability students take four years to get through; the rest take an AP course in one of the same subjects, or an elective. History has a four-course sequence over three years, and can’t take an AP course again, which is too bad.

High school math has a six-course sequence that students enter at different points–five course if you count algebra 2/trig as one. From geometry on, each course has an honors version. Calculus is generally offered in both general and AP versions AB and BC. Algebra often has a support course. Then there’s statistics and AP Stats, and usually Business Math. Toss in Discovery Geometry. What is that, 17? And unlike ELL vs. regular English, we math teachers cover it all.

English and history high school teachers rarely have more than two preps, often a primary and secondary. I won’t say never. Science teachers are the most likely to have single preps, or general and honors in the same subject, because they have specialized credentials.

Math teachers often have three preps. Larger high schools may have more specialization. Maybe in big schools you’ll hear someone described as a geometry teacher, or a calculus teacher. But that’s just never been the case in any school I’ve seen.

To the degree math teachers do specialize, it’s a range of the 6 year sequence. The most common is the algebra specialist, a gruesome job that others are welcome to. (It’s only been four years since algebra terrors, my all-algebra-all-the-time year, can you tell? I still get flashbacks.) Some algebra specialists have limited credentials and unlimited patience. Others are genuine idealists, determined to create a strong math program from the bottom up. All of them can go with god, so long as I don’t go with them.

Sometimes you find the high-end experts, the ones that teach AP Calc, honors pre-calc, AP Stats, or some combination of. Sometimes these folk are the prima donnas with the math chops. Other times, they just aren’t very good with kids so they get stuck with the most motivated ones—they also teach the honors algebra 2 and geometry courses sometimes, because they just can’t deal with kids who aren’t as prepared or motivated. (No, I’m not bitter. Why would you think that?) And while we don’t have a name for what I do, it’s not uncommon for a math teacher to focus on “the middles”, the courses from geometry to pre-calc.

But not all schools go the category route. Others require all math teachers to cover a low, mid, and high level course in the sequence to be sure that no one gets cocky.

So now, after that explanation of preps, go back to the beginning, when I mention my hyperventilation over easy, familiar preps that I thought would be boring. Many teachers would agree—quite a few colleagues in all subjects commiserated with my dismay. Other teachers consider it rank abuse of power when admins assign them two preps, much less three.

Why? Because some teachers love the additional workload, love building and developing curriculum, mulling over the best way to introduce a new topic. For teachers like me, that’s an essential element of teaching—and repetition, teaching the same content three or four times a day, is so not essential, but rather Groundhog Day tedious. Others see curriculum as something they want handed to them or will do, reluctantly, once. Or, something they’ve honed after umpty-ump years and it’s perfect so they aren’t changing a thing. To these teachers, curriculum is a distraction from their primary job of teaching, the delivery of that curriculum–the job they actually get paid for. Give them the day of the school year, they know what they’re teaching.

If you’ve never really considered teacher preps before, certain questions might come to mind. Does teacher effectiveness (however measured) vary with the number of preps? Does teacher effectiveness vary by subject? (I’ve wondered before if I’m just better at geometry than algebra, for example.) Could we improve academic outcomes by giving weak teachers one prep in a limited subject, and strong teachers multiple preps (assuming we know what that is)? Do teacher contracts negotiate the maximum number of preps that can be assigned? While Ed’s informed assertions are interesting, surely there’s better data that gives a better idea of how many preps high school academic teachers have, on average? Or middle school teachers?

What terrific questions. They all occurred to me, too. And while I’m a pretty good googler, I began to wonder if I wasn’t using the right terms, because I could find no research on teacher preps, no union contracts restricting preps.

Let’s assume that some research has been done, that some contracts exist but escaped my eagle Google. Teacher preps still are clearly not on the horizon. I can’t remember ever hearing or reading a reformer mention them. When I was in ed school, the subject never came up—how to identify the best combination of preps, what number was optimal, and so on. Given how little control teachers have over preps, ed schools may just count it as one more of the nitty-gritty elements of the job we’ll discover later.

Education reformers simply don’t understand the degree to which teachers develop or influence curriculum and the resources it takes. They don’t understand the tremendous range of curriculum development that takes within a school. Moreover, most reformers don’t even understand that preps exist or have any impact on teacher workload. Few of them ever taught at all. So they don’t really know what a “prep” is, and then assume that most teachers rely largely on a textbook. That doesn’t leave them much room to mull.

Researchers don’t discuss preps much, either. I’m not even sure Larry Cuban, who describes teacher practice better than almost anyone, describing here the multi-layered curriculum which explicitly describes teacher-designed curriculum, has never written about preps. Many researchers also tend to confuse textbooks with curriculum.

I wonder if researchers are prone to ignoring high school preps because they would have to acknowledge how questionable their conclusions are without taking preps into consideration. If a researcher compares two high school teachers using a new curriculum, does it matter if one teacher has one prep and is teaching the same topic all day? This may give that teacher more time to adjust, notice patterns, change instruction. Meanwhile, the busy teacher with three preps who is just teaching one class with the new curriculum may just be doing it as an afterthought. Alternatively, teaching one class all day may also bore the teacher to the point of rote delivery, while the teacher with one class jumps in with enthusiasm.

Once I really started thinking about preps from a policy perspective, I became really flummoxed at the lack of play it gets. I may be missing a whole field of research, that’s how odd it is.

Administrators keep preps firmly in mind; whether contracts require it or not, they rarely give high school teachers more than whatever a commonly agreed amount is (usually three). Ideally, they will limit new teacher preps, although my mentee from last year had three preps each semester. Now that I think on it, I had three preps, too. Never mind—they pile it on newbies, too.

If VAM ever gets taken seriously at the high school level (which I find very unlikely), preps are likely to become a contract issue. Teachers being judged on test scores will probably demand a large sample size, which means fewer preps.

Fewer preps for teachers, of course, means far less flexibility for administrators putting together the dreaded master schedule. Ultimately, it means more teachers on the pay roll or fewer courses offered, because fewer preps and less flexibility must be compensated for somehow.

And hey. I just realized that Integrated Math (bleargh) schools have fewer preps. Maybe this is another foul plot of Common Core.

For myself, I do not want limited preps, even if my feet are forced to the fire on the point that hey, I’m really enjoying this easier year. But honesty compels me to point out that preps should be explored for their impact on teacher satisfaction, teacher productivity and–to the extent possible–academic outcomes.

I have no real ideas here. Only thoughts to offer up and see what others have on tap.

However, there’s another issue never far from my mind that perhaps the above mullings cast some light on: that of teacher intellectual property. Stephen Sawchuk just wrote a great piece on various issues in the related arena of teacher-curriculum sharing, and mentioned IP and copyright. I have huge issues with the absurd notion that districts own teacher-developed curriculum, which I’ll save for another post.

But surely this post makes it obvious that if teacher preps vary, then one of two things must be true. Either teachers in the same subject are getting paid the same salary for doing dramatically different jobs–and I don’t mean quality here, just work expectations.

Or teachers are paid to teach, in which case the actual delivery is the same no matter how many preps we have. Teachers then have the choice–the choice–to use the book and supplied materials extensively, or develop their own, to do the job as they determine it should be done. This seems to me to be the obviously correct interpretation of teacher expectations and the “work” they are “hired” for.

And in my world view, teachers are not paid to develop the curriculum, and therefore the district can keep its damn paws off my lessons.


Troubling Students

My classes are easy to pass, hard to do really well in. I’m a pushover for a D, but think three or four times about giving out an A. I didn’t fail a single kid last year. Save for Year Two, All Algebra All the Time, I’ve failed fewer than six kids a year, and even Year Two I had the second lowest fail rate of the math teachers.

I teach mostly math at a comprehensive high school, and the previous paragraph is very near heresy. Some math teachers cheer me on as a brave, admirable soul, but I spot them making the Mano Pantea while they walk away, just in case the Overlord is Watching. Others think I’m What’s Wrong With Education Today. These teachers hold as gospel that math standards could be upheld if we teachers were just willing to fail 60-70% of our students. In contrast to Checker Finn, who thinks teachers like me are spreading out two years of math content over three years of instruction because we can’t be bothered, these folks don’t think I’m lazy. They think I’m soft. They think I’m damaging their ability to cover all the course content they could get through if there weren’t all these kids who shouldn’t be there.

I became a lot less conflicted about my high pass rate–not that I ever lost sleep over it–after teaching precalc and discovering that a third of the kids had forgotten how to graph a linear equation and half couldn’t graph a parabola. These were kids that those other teachers had, teachers who had covered everything. Meanwhile, my kids do well in subsequent classes, so I’m not doing any harm.

But I digress. The students who trouble me aren’t the strugglers. I can take a kid who hates math, doesn’t want to be in class, and get him (it’s usually a him) to try. I can get that kid to attack a projectile motion problem and, even while making multiple small mistakes, beam with pride because by god, he kind of gets this and who ever would have thought? Kids like that, I can pass with nary a qualm.

The worrisome ones pretend they understand, but don’t have a clue. They cheat whenever they can, and not just on tests. They copy classwork in the guise of “working together” or “getting help”, and do their best to sit next to strong students. I group students by ability and, unless they can cheat on my assessment test, they are outed and placed up front, where I can keep an eye on then. They will then ask if they can sit next to John, or Sally, or Patel, their friend, because “they explain it so well”. I say no.

But if they cheated on the test, they can sometimes escape notice for a while. I circle constantly, watching kids work, changing seating when I see too much “consulting” with little discussion. Still others are more clever, and it takes a while before I realize they’ve been cheating not only in classwork, but on the tests–even when I create multiple tests. As a new teacher, I would sometimes miss these kids through the first semester. My success rate at pegging them early has improved.

This isn’t a big group, thank god. I might run into one or two a year. They have a telltale bipolar profile: for example, failing English entirely one year, and passing it the next year with Bs. Passing algebra with straight As, failing geometry completely–and failing the mostly pre-algebra and algebra state graduation test with a spectacularly low score. They aren’t fooling all of the teachers all of the time.

These kids are not your Stuyvesant cheaters, conspiring with others to satisfy demanding parents and create a fraudulent resume to get into a good school. Nor are these the low achievers who just want to get a passing grade in these time units called classes organized into a larger time period called school that others apparently view as a place of learning but they see as little more than a community network in which they have invested considerable social capital.

In fact, they’re almost worse than identified low incentive low achievers, cheating or otherwise. These kids almost seem incapable of learning. I can’t get them to slow down. They often resist help from me. Typical conversation:

Me, stopping by: “Okay, let’s start this again. You’ve plotted these points….”

Student: “Oh, yeah, I see.” Frantically erases.

Me: “Well, hang on, I want to be sure…”

Student: “I got it I got it I got it.” Starts to plot a point, then pauses.

I realize the student is waiting for me to say where to plot it in order to say “Yes, I know, I know.” So I wait. The student takes a deep breath and plots the point then lifts his pencil. “No, that’s not right, duh…”

Me: “You aren’t sure how to plot points.”

Student: “Yes, I am.”

Me: “Great. Plot (7,-7).”

Student plots (-7, -7).

Me: “Stop there.” I go grab a handout I have specifically for these situations, a simple handout that explains plotting points with some amusing activities to drive the point home.

Student: “I don’t need this. I know how to do it!”

Me: “Great. Then it should just take you a few minutes.”

At this point, I get a variety of reactions. Some students become furious. Others get sulky. Still others do the handout, making many mistakes, all the while assuring me that this is easy. I obligingly correct the mistakes, make them do it correctly. The ones that get furious, I shrug and let them continue.

Regardless, within a day, they are making the same mistakes. Nothing sinks in. Don’t get overly focused on plotting points; the problem could be anything–factoring, solving multi-step equations, working with negatives, exponential properties, fractions, whatever. Or a new concept. They have absolutely no clue, and can’t do much of anything.

Yet they don’t have the profile of a low ability student. Test scores, yes. Profile, no. They often have As, win praise from teachers for their teamwork and effort. They are heavily invested in appearing “normal”. Serious control freaks. Sometimes, but not always, with parents who expect success. More often, but not always, Asian. All races. Both genders.

I haven’t taught freshmen since oh, lord, fall 2012.1 I teach relatively few sophomores these days, running into them only in Algebra 2.

That matters because when I taught freshmen and sophomores, I would go full-scale intervention. I might talk to a counselor to see if they should be assessed for a learning disability. I would insist that they stop lying to me and themselves. I had no small success at getting some of them to acknowledge their desperate attempts at fraud, get them to work at their actual level, deal with the discomfort. They didn’t make much progress, but it was real progress, and they had skills to move forward. I ran into some of them again the next year, and we could start on an honest basis and make additional progress. Those who didn’t acknowledge their issues were among the few students I failed.

But that’s a lot harder to do when dealing with juniors taking trigonometry or, god forbid, precalc. Should I fail them? They will probably do better in a class with teachers who give “practice tests”, study guides that have exactly the same questions as the eventual real test but with different numbers. They will definitely do better with teachers who actually grade homework and count it as 25% of the overall.

A small problem. This approach turns my grading policy into: work hard and honestly acknowledge your ignorance and I’ll pass you. Lie and do your best to cheat with similar ignorance and I’ll fail you. I’m comfortable with holistic grading at the bottom of the scale, but I don’t like morality plays.

Then I remember that kids who honestly acknowledge their inability in a trig or pre-calc class are usually seniors, off to junior college and a placement test that will accurately put them in remedial math. I’m only ensuring they are learning as much as possible for free before paying. If they are juniors, I always have a talk with them about their next steps, telling them not to take the next course in the sequence but maybe stats or something else that will keep them working math, but not out of their league.

The kids who cheat and fake it in trig and precalc are usually juniors, and they will be going onto another course. They will not listen to me when I tell them under no circumstances should they continue into pre-calc or, god forbid, calculus. I might be teaching that course, which just gives me the same problem again. Or they’ll be cheating their way through with another teacher–or, that teacher will do what I should have done and flunked them.

This quandary doesn’t make any sense unless you realize that in my view, these kids are pathologically terrified of facing reality, the sort of thing that some of them, forced to face up, might not survive in good form. These aren’t blithe liars gaming the system to look good. Then I remind myself that they’ve been caught before, they’ve flunked other classes, they’ll survive. But I still don’t like the quandary, because these are kids who literally can’t learn. (And remember, I’ve seen them in my non-math classes, too). By junior year, given their denial and fear, does it do any good to make them aware of this? They’re going to be able to point to any number of teachers who disagree with my assessment, and have all sorts of excuses for why they got those Fs. Besides, they just don’t test well. It’s always been a problem.

At times like this, I envy my colleagues who never notice the cheating, or who focus purely on achievement and aren’t interested in the distinctions I’m making.

But these are the students who trouble me.

1Holy Crap. That’s an amazing realization. New math teachers doing your time in the algebra/geometry trenches, take heed. If you want variety, it will come.

Teaching: The Movie

Another entry in “teacher as entertainer”:

Dave of Math Equality writes that Taylor Mali captures his zeal for teaching. Eh. I get vaguely embarrassed when they play Taylor Mali at PD sessions; he’s like teacher martyr porn or something. I naturally have all sorts of teaching miracle stories. But I don’t tell them to inspire you, dear readers, to convince you that here’s another wonderful, self-sacrificing teacher slaving away unappreciated and exploited, yet nobly giving every drop of sweat and blood to to help navigate self and soul to adulthood or sanity, whichever is needed more.

I’m saying “Look, another day at work turns out to be a F***ING MOVIE!” I made more money in tech, sure, but I didn’t ever experience moments where I thought jesus, people would pay money to watch this on screen and not feel ripped off.

Make no mistake: I am the STAR of this movie. I have a contract giving me a guaranteed audience of thirty for 90 minutes, three times a day. They are to be attentive, listen, watch, and if they learn too, well, cool.

Anyway, I had a moment today that many other teachers have had, and for me it was like, I’d have kicked back $20 to the district for the sheer joy of the experience.

It was fourth block, my prep, and I was just about to leave for Starbucks, as is my routine, when Steve, from third block, knocked on the door.

“Hey, why aren’t you in class?”

Steve, white, tall, skinny, glasses, shook his head. “Can’t handle it. It’s insane in there.” He pointed to the class next door.

The class next door is taught by a long-term sub, because we haven’t been able to find a math teacher. But of course, the big pain point for principals is firing bad teachers. (The AVP offered the job to first one, then the other of my interviews, both took other jobs.) This sub is a qualified physics teacher, new to teaching, just got work permit, teaching a brutal schedule (two Discovery Geometry classes. Shoot. me. now.) I’ve talked to her a couple times, given her some advice.

I got up. “Come on.”

Steve shook his head, “No, they’ll know I brought you over. Can I stay here?” I gave him a withering look–sissy!–and as I walked next door I have to admit I envisioned myself pushing open the saloon doors as the sheriff, come to beat this brawl down.

The sub opened the door and gasped, “Thank you for coming!” The room was….not quite a barroom brawl, but kids were talking and chatting and eating, purses and backpacks on their desk covering the handout. They were manifestly not doing math. One big guy with cornrows (and no, not black) in the back of the room was leaning back in his chair, texting. I took his phone and gave it to the sub.

“What are they supposed to be doing?” I asked, softly.

“They are taking a test.”

“A TEST?” Cue Ennio Morricone.

Heads swiveled. I walked to the front of the room, slowly, looking at students. At least ten of them are in my third block class (not math), and they quieted down immediately. Some of the others were still talking. Discovery Geometry is a tough crowd.


“Who are you?”

I just look at him, a big guy, Asperger’s, not malicious. He picked up on a facial cue (hey!) and didn’t demand an answer. The room got quiet in a hurry. Another, smaller guy (this one is black) is perched at the door, half open.

“Are you in this class?”

“Yeah, I have to go the bathroom. Waiting to see what you said.”

“Good plan. You can go. Be back in under two minutes.” To the class, which had briefly started to rustle: “I said QUIET.” Quiet.

“Purses and backpacks on the floor. Now.”

Instant obedience.

“You three are way too close together. You, in red, move to that desk. Then you two spread out. Girls, you in pink sit at the end of the table, other two spread out.” Again, obedience.

“You work the test in silence. I don’t want to hear about any problems. Next time I come here, it’s with an administrator. Is that clear?”


“Get to work.” They all instantly bend over their tests, except Texting Kid, who raised his hand.


“Could I have a pencil?” (Keep in mind, he’s had the test for 20 minutes.) He got a pencil, and got to work.

I left as Bathroom Guy comes back, well under two minutes.

Steve hustled back to the test, gratefully, after taking my cell and room phone number so he could text or the sub could call me in the event of future disaster.

I never did get to Starbucks, so did some copying. On the way back to my room, who should I run into but Bathroom Boy.

“Hey. What are you doing out?”

“Had to go to the bathroom.”

“You already did that.”

“Had to go again.”

“Yeah, no.” Walked him back to the room. He didn’t even protest. I told the sub no one, but no one without health issues, goes to the bathroom twice in one day. They’d finished the test, and with fifteen minutes left in class, they were talking loudly with nothing to do. I told her no to that, too, in the future. But they’d worked harder and more quietly than ever before, she told me.

I remember an actor saying that in a performance if you have to cry, you can either dredge up a horrible memory or just use an onion. This was all onion. And yet it was also a good fifteen minute’s work. Kids learned someone was watching; they know it’s not free beatdown on sub week. But the whole time I was thinking “Oh, my god, this is SO COOL. I’m CLINT. Or at least the badass principal in The Wire.” Self-absorbed puppy that I am, there is my takeaway.

I am teaching two brand new classes, and an Algebra 2/Trig class I’m struggling to keep somewhat true to its name. It’s not an easy year, I’m not brimming with confidence—although I’m having a great time. So getting to be Clint or the badass principal was just a great moment, a reminder I still have teacher mojo.

Right about now, I realize son of a bitch, I’m a lot more like Taylor Mali than I’d like to think. Yes, I’m more Movie Star than Teacher Martyr, more audience participation than individual redemptions. But ultimately, I’m one of those teachers who can walk into a room of adolescents and command them—-to learn, to think, and sometimes just to obey. And just like Taylor Mali and the people clapping him on, I like what that says about me.

And hell, if you think it’s easy, you try it.

Teaching Math a Third Way

I was reading Harry Webb’s advice to a new secondary teacher, describing his usual classroom procedure for “senior maths”, as an addendum to his earlier post on classroom management. And I thought hey, I could use this to fully demonstrate the difference in math instruction philosophies.

Harry’s lesson is a starting activity, a classroom discussion/lecture, and classwork.

So here’s what I did on Friday for a trig class, which is certainly “senior maths”: brief classroom discussion, class activity (what Harry would call “group work”), brief classroom discussion. And I think it’s worth showing that difference.

The kids walked in, sat in assigned seats grouped in fours—strong kids in back, weakest in front. I often forget and start before the tardy bell, just laying out what we’ll do that day. I never check homework—the kids take pictures and send it to me, and I eventually get it into the gradebook. I don’t really care if kids do homework or not. They take pictures of it and text or email me. I eventually check. If kids have homework questions, they’re to let me know during the tardy pause and I’ll review them on an as-needed basis. But yesterday, the kids hadn’t had homework, so not an issue.

When the tardy bell rang, I had just finished sketching this:


(this next bit is what I think Harry would call classroom discussion):

“Can anyone tell me the relationship these triangles have?”

I got a good, solid chorus of “similar” from the room—not everyone, but more than a smattering. I picked on Patti, up front, and asked her to explain her answer.

“They have two congruent angles.”

“Good. Dennis, why do I only need to know about two of the angles?”

Dennis did the wait out game, but I’m better. After a while, he said, “I don’t know.”

“Do you know how many degrees are in a triangle?”

“180. Oh. OK. If they add up to 180, and two of them are equal, the third one has to be the same amount to get to 180.”

“See, you did know. Jeb, if two triangles are similar, what else do I know?”

Jeb, in the back corner, said “The sides have a constant ratio.”

“More completely, the corresponding sides of the triangle have a constant ratio. Good. How many people remember this from geometry?” All the hands are up. “If you had me for geometry, and about eight of you did, you may even remember me saying that in high school math, similarity is much more important than congruence, for high school math, anyway. Trigonometry will prove me right once again. So while I hand out the activity, everyone work the problem.”

When I got back up front, I confirmed everyone knew how to solve that, then I went on to this:

“I don’t want everyone to answer right away, okay? I’ll call on someone. Give people a chance to think. Which one of these variables can be solved without a proportion? Olin?”

Olin, very cautiously: “x?”


“I can just…see what I add to 8 to get 12?”

“Right. Now, that probably seems painfully obvious, but I want to emphasize—always look at the sketch to see what you know. Don’t assume all variables take some massive equation and brain work. Now, how can I find the length of the other side? Alex?”

“I’m just trying to figure that out.”

“You’re assuming the triangles are similar? Can she do that, Jamie?”

“Yes, because the lines are parallel.”

“Hey, great. Why does that help, Mickey?”

“I don’t know.”

“Cast your mind back to geometry. Which you took with me, Mickey, so don’t make me look bad. What did we know about parallel lines and transversals?”

“Oh. Oh, okay. Yeah. the left angles are congruent to each other, and the right ones, too.”


“Corresponding angles,” said Andy. I marked them in.

“Okay. So back to Alex. Got an equation yet?”

“I don’t know what I should match with what.”

“Okay. So this, guys, is the challenge of proportions. What will give me the common ratio that Jeb mentioned? I need a valid relationship. It can be two parts of the same shape, or corresponding parts from different shapes. Valicia?”

“Can I match up 8 and 6?”

“Can she?”

“Yes,” said Ali. “They are corresponding. But we don’t know what the short leg is.”

“We don’t need to,” says Patti. “6 over 8 is equal to y over 12.”

After finishing up on that problem, I turned to the handout.


“I stole this group of common similar triangle configurations, just as a way to remember when they might show up. But we’re going to focus on the sixth configuration. Can anyone tell me what’s distinctive about it?”

“It’s a right triangle with an altitude drawn,” offered Hank.

“True. Anything unusual?”

“No. All triangles have altitudes.” He looked momentarily doubtful. “Don’t they?”

“They do. So take a look at this” and I draw a right triangle in “upright” position. “Where do I draw an altitude?”

“You don’t need to….Oh!” I hear talking from all points in the room, and pick someone up front. “Oscar?”

“That’s the altitude,” he points. I wait. “The—not the hypotenuse.”

“Melissa? Can you give me a pattern?”

Melissa, in back, quite bright but never volunteers. “If the leg is a base, then a leg is the altitude.”

“True for all triangles?”

“No. Just for rights. Because the legs are perpendicular.”

“Right. So back to Oscar, what’s different about this?”

“The hypotenuse is the base.”

“Right. So it turns out that the altitude to the hypotenuse of a right triangle is….interesting. Turn over the handout.”

The above conversation, which takes a while to write out, took about 15 minutes, give or take. I would expect Harry Webb has similar stories.

The next part of my lesson is the “group work” that Harry and other traditionalist think leads to “social loafing” and wasted time.


The kids are in ability groups of four; they go to whiteboards spaced all around the room: two 5X10s, 3 4x4s, and self-stick on bulletin boards that works great—I even have graphs attached.

And I just give them instructions and say, “Go.”

Is this discovery math? Hell, no. I give them all sorts of instructions. I don’t want open-ended exploration. What I want for them is to do for themselves and understand what I would have otherwise explained.

In the next 50 minutes, using my instructions, each group had identified the three triangles:


There’s always a surprise. In this case, more of the kids had trouble proving the similarity (that is, all angles were congruent) than with the geometric mean. I actually stopped the activity between steps 1 and 2 to ensure everyone understood that the altitude creates two acute angles congruent to the original two–which I frankly think is pretty awesome.


Even before they’d quite figured out the point of the angles, they’d gotten the ratios:


Each of the nine groups found the second step, proving the altitude (h) is the geometric mean of the segments (x & y) on their own; I confirmed with each group. Once they’d established that, I reminded them that the third step was to prove the Pythagorean theorem and to look for algebra that would get them there. Four of the groups had identified the essential ratios, identifying that a2 = xc and b2 = yc.

At that point, I brought it back “up front” and finished the proof, which requires three non-obvious steps.

a2 + b2 = xc + yc (reminding them about adding equations)

Then I waited a bit, because I wanted to see if the stronger kids pick up on the next step.

“Just think, a minute. Remember back in algebra II, when you were solving for inverses.”

“…Factor?” says Andy.

“Oh, I see it,” Melissa. “factor out the c.”

“Right. So then we have a2 + b2 = c(x+y)”

“Holy sh**.” from Mickey.

“Watch the language.”

“That is so cool.” says Ronnie, who is UP FRONT!

“if you don’t know what they’re saying, everyone, look at the diagram and tell me what x+y is equal to.”

And then there were a lot of “Holy sh*–crap” as the kids got it. Fun day.

I wrapped it up by reminding them that we were just doing some preliminary work getting warmed up to enter trig, but that they want to remember some key facts about the geometric mean, the altitude to the hypotenuse of a right triangle. Then I go into my spiel on the essential nature of triangles and we’re all done. Homework: Kuta Software worksheet on similar right triangles, just to give them some practice.

This lesson would rarely be included in a typical trig class, whether reform or traditional. I described the thinking that led to the sequence. But it’s a good example of what I do. (Also, as many bloggers have pointed out, my attention to detail is dismal, both in blogging about math and teaching it. Kids usually pick up on stuff I miss, and if it’s something big, I go back and cover it.)

I vary this up. Sometimes I go straight to an activity they do in groups (Negative 16s and Exponential Functions), other times I do a brief classroom discussion/lecture first (modeling linear equations and inequalities). Sometimes I have an all practice day or two—I’ve covered a lot of material, now it’s time to work problems and gain fluency (that’s when the tunes come out).

I originally had more but somehow the length got away from me, so I’ve chopped this down.

I have developed this method because I was never happy with traditional math, whether lecture or class discussion. The difference is not solely about the method of delivery; my method requires more time, and thus the pace is considerably slower.

The jury’s in on reform math: it doesn’t work well in the best of cases, and is devastatingly damaging to low ability kids. Paul Bruno refers to reform math as the pedagogy of privilege, and I agree. But it’s worth remembering that reform math evolved as a means of helping poor and black/Hispanic kids. Why? Because they weren’t interested in traditional math methods, and were failing in droves.

Ideally, we would stop forcing all kids into advanced math. But since that’s not an option, I think we need to do better than the carnage of high school math as we see it today: high failure rates, kids forced to repeat classes two or three times Given the ridiculous expectations, traditional math is due for some scrutiny, particularly in its ability to leave behind kids without the interest or high ability to carry them through. Let’s accept that most kids can’t really master advanced math. We can still do better. This is how I try for “better”.

I still have problems with students forgetting the material. I still teach kids who aren’t cognitively able to master higher level math. I’m not pretending the problems go away. But the students are willing to try. They don’t feel hopeless. They aren’t bored. I don’t often get the “what will we use this for” question—not because my math is more practical, but because the students aren’t looking for an argument. (And when they do give me the question, I tell them they won’t. Use it.) However, as I mentioned in the last post, I now have had students two or three years in a row. They were able to pass subsequent classes with different teachers, but they haven’t lost the ability to launch into an activity and work it, having faith that I’m not wasting their time. That tells me I’m not doing harm, anyway.

Opening Day as Opening Night

I really like our late start; why the hell are so many school districts kicking off in early August? (They want higher test scores, Ed.)

Anyway, I’m teaching trigonometry for the first time. In every course, I assess my kids on algebra I, varying the difficulty of the approach based on the level of math. What to do with trig? My precalc assessment was too hard, my normal algebra assessment too easy—or was it? I didn’t want to discourage them on the first day, but I also didn’t want to give a test that gave them the wrong idea about the class’s difficulty level. After much internal debate, I created a simplified version of an early algebra 2/trig quiz. I dropped the quadratics (we only had 45 minutes). Then, just to be safe, I made backup copies of my algebra pre-assessment. If the kids squawked and gave too much of the “this is too hard” whine, I’d be ready.

And so in they came, 23 guys, many of them burly, a few of them black, none of them both, and 11 girls. Fully half the students I’d taught before, two of them I was teaching for the third time. (one poor junior has only had one high school math teacher.) Perhaps their familiarity with me helped, but for whatever reason they charged right in and demonstrated understanding of linear equations, systems, a shaky understanding of inequalities, and willingness to think through a simple word problem. Good enough. Great class—rambunctious, enthusiastic, way too talkative, but mostly getting the job done.

I’m still not much of a planner, which is why I gave no thought to my trig sequencing until I saw how they did with the assessments. If they’d tanked, I would have done a simple geometry activity to give me time to regroup, start after the weekend with some algebra. But they didn’t tank, so how did I want to start?

Special Rights. Definitely. I would use special rights to lead to right triangle trig. All clear. But how to get to special rights? Algebraic proof of the ratios. But why special rights? It seems random to start there. As long as I’m going to be random, and since trigonometry has something to do around the edges with right triangles, why not start with right triangles? At that moment, this image popped into my head:

Hey. One step back to geometric mean, and I’ve got a nice intro unit all set up.

So the next day, I started with this:


Note: I told them the questions were separate—that is, the square was equal only to the area in #1 and only to the perimeter in #2.

I wasn’t happy with the questions. They gave too much away. But every rewrite I tried was even more confusing, and in a couple cases I wasn’t sure it was an accurate question. Besides, on the second day of school, you want to release to something achievable. Better too straightforward than have the kids feel helpless this early.

And it went great. Top kids finished in under five minutes; I had them test out the process for cubes vs rectangular prisms. All the rest completed the work in 15 minutes or less, with some needing a bit of reassurance.

I had to prompt them to recognize that the perimeter to side relationship is the “average” algorithm (that is, the arithmetic mean). “If I add two numbers and divide by 2, what is the result?” I think I noodged for a few minutes before someone ventured a guess.

I followed with a brief description of geometric mean, reminded them of the various measures of central tendencies, pointed out that now they all knew why the SAT followed “average” with arithmetic mean. Finished up with practice problems.

I was stumped briefly when a student noticed that the arithmetic mean always seemed larger. Argghh, I’d mean to look that up. I told them I’d look up the answer and get back to them. Meanwhile, I wondered, could the two means ever be equal? I made the stronger kids do some algebra, and let the others just talk it through.

Great lesson, not so much from the content, but from the energy. Look, I was winging it. I do that when I have a good idea that isn’t fully fleshed out. I cut back goals, keep things very simple, and watch for opportunities. I always advise new teachers to avoid mapping things out—they are often wasting time, because things will go off the rails early in some cases. Keep it broad, tell the kids that you’ll adjust if needed, and go.

The rest of the opening “unit”: a brief review of similarity and then use of geometric means in right triangles, leading to my favorite of the Pythagorean proofs. Then onto special right triangles, deriving the ratios algebraically. This puts things nicely in position for introduction of right triangle trig and I can drop in a quiz. Well, I’ll probably put in a day of word problems first.

After school today I ran into a group of football players waiting for practice to start, many of them previous students and two of them currently in that trig class. After hearing what they were all up to, how their summers had panned out, what the team’s chances were, Ronnie, one of the two current students, said, “I’m glad I have you; I would hate to be dumped for low grades my senior year.”

“Ah, yes, that’s my claim to fame. I’m not a great teacher, but by golly, I give passing grades.”

Shoney, the other of the two, a big, burly, not black senior, was laying along a school bench calmly watching the conversation, and spoke for the first time.

“You know. Trig was….fun today. It really was.”

Ronnie nodded.

The point is not oh, gosh, Ed is a fabulous teacher who makes kids love math. That’s never my goal, and it’s not what Shoney meant.

Recently, Steve Sailer writes that “school teaching can be thought of as a very unglamorous form of show biz, which involves stand-up performers (teachers) trying to make powerful connections with their audiences (students)”. He’s right. Education and entertainment are both, ultimately, forms of information transmission.

His next paragraph is dead on, too:

We are not surprised that some entertainers are better than other entertainers, nor are we surprised that some entertainers connect best with certain audiences, nor that entertainers go in and out of fashion in terms of influencing audiences. Moreover, the performances are sensitive to all the supporting infrastructure that performers may or may not need, such as good scripts, good publicity, and general social attitudes about their kind of performance.

People tend to construe the “education as entertainment” paradigm as “show the kids movies all day” or “keep the kids laughing”, but just as all entertainment isn’t comedy and happy endings, so too is education more than just giving the kids what they want.

I’m a teacher. I create learning events. I convince my audience to suspend disbelief, to engage. Learning happens in that moment. Some of the knowledge sticks. Other times, only the memory of learning remains, and I’m starting to count that as a win.

And so the year begins.

A Talk with an Asian Dad

Summer enrichment ended two weeks ago. I enjoyed my classes as always, although the commute, now that I’ve moved, was brutal. Not sure I’ll take it on next summer, but that’s a while away.

On the last Monday Nick asked me if I’d speak to his dad.

“I’m happy to, but you have to run it by the director.”

At Kaplan, parent management is turned over to the tutor. Not so here, or at other hagwons I’ve known of. At first, I assumed the company just didn’t want parents trying to privatize the tutor and cut out the middleman. Until six years ago, when a parent whose child I was tutoring in APUSH got my number somehow and called me fourteen times, leaving agonizingly long messages giving her schedule to ask when I could meet, asking over and over again if I could meet more frequently, telling me she’d call at x o’clock, then calling up to cancel the scheduled call, asking for a report on progress each day, wondering idly if I could meet directly with them but assuring me she couldn’t afford high fees—all during a 3-day period after I’d met with her daughter for the first time. I told my boss, he threatened to fire the parent, I didn’t get any more calls.

Run all parent contact by the director. This is a rule I follow.

So after class the next day I sat down with Nick and his dad, a genial Indian gentleman.

“I wonder if you could advise me on how best to prepare Nick for the PSAT this fall.”


“No practice? No classes?”

“He’s a sophomore. He was solidly over 600 on both reading and writing, over 750 on math, in all our practice tests—which are skewed difficult. If for some reason he gets lower than 60 on any section, I’d be shocked, but not because he was unprepared. He shouldn’t go back to PSAT practice until late summer or fall of junior year—he’s definitely in National Merit territory, so he’ll want to polish up.”

“But wouldn’t it be better for him to practice?”

“No. If he gets below 60–even 65–then look closely at his results. Was he nervous? Or just prone to attention errors? But it won’t be lack of preparation.”

“Oh, that makes sense. We are trying to see if he has any testing issues.”

“Right. Content isn’t a problem. I don’t often get kids scoring over 600 in reading and writing in this class. Which brings up another issue. I want you to think about putting Nick in Honors English and Honors World History.”

“English? That’s not Nick’s strong subject.”

“He’s an excellent writer, with an outstanding vocabulary, which means he is ready to take on more challenging literary and composition topics.”

“Really?” Dad wasn’t dismissive, but genuinely taken aback. “He gets As, of course, but I get glowing reports from his math and science teachers, not English and history. Shouldn’t he focus on science and robotics, as well as continue programming?”

“If Nick really loves any of these subjects, then of course he should keep up his work. And please know that I’m not suggesting he give up math and science. But his verbal skills are excellent.”

“But I worry he’ll fall behind.”

“He’s starting pre-calculus as a sophomore. And that’s the thing….look. You know as well as I do that Nick’s college applications will be compared against thousands of other kids who also took pre-calculus as a sophomore. His great verbal skills will stand out.”

This point struck home. “That’s true.” Dad turned to Nick. “Are any of your friends taking honors English?”

“No, most of the kids taking honors English aren’t very good at math.” (Nick’s school is 80% Asian.)

“But shouldn’t he just wait until his junior year, and take Advanced Placement US History?”

“Nick. Tell your dad why I want you to take these classes, can you?”

Nick gulped. “I need to learn how to do more than just get an A.”

“Isn’t that enough?”

I kept a straight face. “No. Nick is comfortable in math and science classes. He knows the drill. But in English and history classes, he’s just….getting it done. He needs to become proficient at using his verbal skills in classes that have high expectations. This will be a challenge. That’s why I want him to start this year, so he can build up to the more intense expectations of AP English and History. He needs to learn how to speak up in school at least as well as he does here…”

Dad looked at Nick, gobsmacked. “You talk in class?”

“….and learn how to discuss his work with teachers, get a better sense of what they want. Remember, too: Nick’s GPA and transcript is important, but ultimately, he’ll want to be able to perform in college and beyond, as an employee or an entrepreneur.”

Dad nodded; he got it. “He needs to write and read and think and express his thoughts. And this will help. Hmm. This has been most helpful. So he shouldn’t do any SAT prep this fall?”

“He shouldn’t do any SAT prep this year.”


On our last day, I showed The Sixth Sense, which went over very big.

“Okay, I want you to heed me well on this. You must never tell anyone the ending.”

“You mean that he’s a….”

“STOP! Yes. That’s what I mean. Some movies—and it’s a small list—have surprises that take you out of the conventional, that take the story in a direction you never dreamed of anticipating. Tell people and you’ve robbed them. Never tell.”

“It’s like giving away the ending?”

“Worse. So, kids, we’re at the end. I’ve loved working with you. Do your best to take away the lessons from the summer. Speak up! Don’t just sit like a lump. Have ideas. Ask yourself what you think. Keep aware of what’s going on in the world. Remember that a 4.0 GPA has no bearing on whether you’re an interesting companion or a valuable ally in a bar fight.”

“But my parents…” Lincoln starts.

“Ahahah. Stop. I’m not telling you to disobey your parents. But your decisions, ultimately, are your own.”

“You don’t know what it’s like.”

“You’re right. But I can give you a strategy, provided you promise never to say it came from me.”

“Get caught cheating?”

I look around for something to throw. “That’s not even funny. DO NOT CHEAT. I know you have pressures and it feels like the easiest way to have a life and keep your parents off your back.”

Way, way too many nods.

“Don’t. I mean it. Never mind the morality, never mind how deeply wrong it is. Every time you cheat to get that better grade, you are adding to the pressure you already feel.”

Wide eyes.

“Anyway. Here is a strategy. First, you have to make an appointment with the counsellor at your school. The white counsellor.”

“But my mom always tells me to go to the Asian counsellor.”

“Yes, I know. For this, you need a white counsellor. Then you prepare. Irene, you take in your notebook, and have it open to all sorts of dark, depressing pictures. Ideally, one with you sitting in a corner, distraught. The rest of you don’t have that out, but make yourself look sad, and exhausted.”

“I am exhausted.” from Ace.

“And if I get a B, I’ll be really sad,” said Ben.

“So it should be easy. Then you tell the counsellor how much pressure you feel, how you feel like you can’t ever screw up, that your parents will be sooooooo disappointed if you ever don’t get an A, that you sometimes can’t sleep thinking about how much they expect, and how bad you are for letting them down, by not being perfect. The counsellor will want to contact your parents. You look horrified at first, say they’ll be angry. The counsellor will back off, and then try again. You reluctantly agree. The resulting meeting will be something your parents will not want to repeat. They will either soften their behavior, or take you back to China, Korea, India, wherever, so they don’t have to deal with these crazy soft white people.”

They’re all howling with laughter by this point.

“Because remember boys and girls, in white people world, Asian parenting styles shock and appall. If you went to a white therapist, that therapist would tell your parents to stop.”

“Oh, god, that makes me laugh just thinking about their faces.” Irene says. “I’d never do it, of course.”

“But at least I can think I have a choice,” from Ellen.

“Exactly. Which is my point. Choose to become genuinely well-educated and thoughtful people. Don’t be satisfied with a report card that lies about you. Now, get out of here. Enjoy the dregs of summer.”

Nick stayed behind.

“My dad is changing the spreadsheet.”


“He has a spreadsheet with my classes through senior year.”


“I’m taking honors English and history this year, instead of a second independent studies project. Then he’s moving the pretty easy biotech class to junior year, and AP Chem to senior year. And I’m going to take a programming course during the summer, rather than during school. That way I’ll be able to focus on AP English and US History as well as BC Calc next year.”

“How’s it feel?”

“Really good.” His beam matched mine. “I’m going to try and talk him down to AB Calc, even. Thanks for helping out.”

One dad at a time.