Cutting Up Your Melon

A couple of years ago, we had some friends over for dinner and I was cutting up watermelon for a recipe. While doing so, I thought of a math problem and posted it on Facebook. It went like this: A recipe calls for 4 cups cubed, seedless watermelon. I am trying to double the recipe and am having trouble getting cubes out of the watermelon pieces. What is the best way to cut 1/2 inch cubes so that I use as much of the watermelon as possible? For simplicity’s sake, go ahead and assume the watermelon is a perfect ellipsoid. Continue reading


Give to Cesar the Things That are Cesar’s …

I wrote this letter to a teacher at my previous school who was having trouble reconciling what she was taught about implementing grades and standards and tests into instruction, and what the school does as an innovative project-based learning school. The principal at the school, referred to as Tanya, tells the staff that grades are based on mastery of content, not amount of work turned in, or extra credit, or effort. This was confusing to Kristen because she was having a hard time identifying where this was happening in practice. I wrote this letter to try and help. Continue reading

Bare Bones Lessons: Fractal Building

This is an activity I did as part of a large, multidisciplinary project I taught about fractals and architecture. You can use it in any kind of project or unit where you are using fractals in some way or just want to expand some mathematical concept that can be applied to this. You can get as deep as you want with the math or keep it somewhat basic.

Grade Level: 5th – 12th

Materials: Sugar Cubes, glue, cardboard. Continue reading

Accidental Radical

“Hi, Mr. Thayer. Come have a seat. I called you in to talk about some complaints I have received from some of the parents. Do you know what they are about?” I did know, or at least had an idea, but I have always hated this guessing game that principals and teachers liked to play with me throughout the years, always trying to get me to tell them why I was in trouble so that they could avoid initiating the confrontation. That if I could just spell out for them why it was that their authority even mattered, they might be saved from some kind of embarrassment, or arrive at some revelation that would justify the role they were now unconvincingly playing. But yes, I knew after back to school night that parents were mad because they sat glaring at me while I gave my speech about the class, and then refused to shake my hand when they left, apparently to march straight to the principal’s office. Continue reading