Great Classroom Action


Cathy Yenca offers her student “two sheets of paper, some tape, a ruler, a calculator, and a little bit of breathing room” and the two of them make math happen:

Clearly, the student was delighted that his calculations matched what happened in the video. I said to him, “E., so you learned a little something about volume today, eh?” His response, without hesitation: “Always go with the fat one.”

Rachel Kernodle posts a clever illustration of inverse functions.

Sam Shah shares his struggle to make related rates interesting and finds some solutions:

Then I asked our esteemed volunteer to use one breath to blow up the first balloon. Taped it up. Again, for two breaths. Taped. Et cetera until we got a total of six balloons taped. Then I asked what things are measurable in the balloons. Bam. List.

Bruce Ferrington asks, “How Tall Is Our Class?” a question which is surprisingly involved:

So, how were we going to measure the height of a class? Well, the kids came up with three suggestions.


I’m Dan and this is my blog. I’m a former high school math teacher and current head of teaching at Desmos. More here.