Last year, I did this lesson with my class on Feynman’s Blocks analogy for Energy. While I liked the lesson back then, I felt like was a lot of me talking, and not much student engagement. I tried to make some small changes to that this year, by pausing and having students explicitly think of what things they’d need to know to determine the number of blocks in the toy chest, then define variables for each quantity, and finally come up with an equation. This turned out to be far more successful then when I simply tried socratically polling the class, and one or two kids shouted out the answer last year. We also got into some great discussions about variable naming conventions and units. The other thing I tried to be better about was emphasizing the big picture of what we are seeing—this equation has 9 variables and it looks super complicated, but the idea it is trying to tell us—Energy Conservation—is so very simple. One last thing that probably help rout at the end was giving them the formula for Kinetic Energy and asking make measurements that would let them determine the kinetic energy of a moving robot, which turns out to be tiny compared to a peanut or even a battery.