Category Archives: Algebra

When I Got Them To Beg

A quick flip to the quadratics section in each of the six textbooks lying around here I find at least one problem about finding the width of some border. The concrete around a pool, the walkway around a garden, the frame around a picture, the border around a rug. I present to you the collage. […]

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Des-man

Just how fabulous is Desmos. Following up on last Friday’s lesson, I had the kids create “Des-man” on Desmos. I made these very simple sketches, showed them to the kids, and told them the minimum requirements: face and mouth must be parabolas eyes and nose are linear equations Not only was this so great to reinforce slope, y-intercept, and all the coefficients, it also […]

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Students Embroiled in Conway’s Rational Tangles

Me: We’re going to do an activity today. Jonathan: Let me guess. It’s your favorite activity. M: How did you know that? J: You say that about everything we do. M: You have a problem with that? J: No. But I’ve lost track of how many favorites you have. M: And I’ve lost track of how many […]

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Stack ’em High

My algebra kiddos are doing Dan Meyer’s Stacking Cups because Andrew Stadel did the lesson and wrote glowingly about it. But Andrew used only one-size cups, I used three (that’s three!) different sizes. Who’s better now. Just eyeballing I ask students to look at me, look at this 12-oz Styrofoam cup that I’m holding, and estimate how many cups they […]

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The question was mine, but the answer was all his.

I carry a defective teacher gene that makes me intolerant of pacing guides and curriculum guidelines. I’m sure I’m a month behind in the pacing guide, and I’m pretty sure no part of today’s lesson will appear on any state test. But I did it anyway. The algebra kids have been doing a lot of […]

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Lego Pieces and Feasible Region

This afternoon I came across a tall stack of Lego® boxes stored in my son’s closet; they reminded me of a lesson. (My son just turned 20 three days ago. I can still see him playing with his Lego sets for hours on end when he was younger. And when he ran out of floor space […]

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More Rectangles and One Good Read

I just started reading this book on Ramanujan, and I highly recommend it. Curmudgeon just posted this Painter’s Puzzle yesterday on Christmas Day — what a nice gift for us! A painting contractor knows that 12 painters could paint all of the school classrooms in 18 days. They begin painting. After 6 days of work, though, 4 people were added […]

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Parallel and Perpendicular Lines

Bleh. I don’t know of a clever way to teach parallel and perpendicular lines. I’ll try asking kids questions and maybe their answers will guide me and make me look smart until 2:50 p.m. Me: Using your arms, show me parallel lines. They do. One boy clasps his hands together like he’s praying. M: What […]

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My Gratitude and One Share

I sat down wanting to share a lesson I did in Algebra on Friday, but I’m weepy because it’s Veterans Day. Please allow me to share this first. I love this country. I love the America that welcomed me and my brothers and sisters with open arms 36 years ago. I love Mrs. Schnettler for patiently teaching […]

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Using Excel for Problem Solving

One of the more enduring lessons that I do with my algebra class is having them use Excel for problem solving. Don’t know why I haven’t written about it as I’ve been teaching this strategy for at least 5 years now. (I don’t recall reading other teachers’ blogs about using Excel this way either. Please let me know if you […]

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