On a recent blog where I talked about error correction, Steve Grossberg reminded me about the Math Mistakes game. I had used this once before in Physics, but it was less of a success than I had hoped for (I was really excited about it, but the “game” just flopped in class). However, I hadn’t tried it with my advanced Precalculus class, and I must say that it went over pretty well!
It’s great for the setting of proofs in trig identities, however I had my students create the math mistakes on your standard 2′ x 3′ whiteboard. Then, the next day, as they finished the quiz, they went one by one over to the “Math Mistakes Gallery” and looked for mistakes. When they discovered a hidden mistake, they would write it down on their paper. Once everyone got a chance to look through the gallery, we came back together and discussed what people found. I even tallied up how many people found each mistake, and the “winner” was the person whose mistake was hidden the best. Here’s the winner:
A Tricky Mistake! Also hard to read…
We even had a discussion about how good the mistakes were and what made them good! We decided that the winner won because he put the mistake during multiplying the binomials, and students don’t like to multiply binomials (at least they admit it).
This variation–“Gallery Mode”–is good because it allows students to work at their own pace, AND it allows students to work and think the entire time. Nobody discovered all of the mistakes, and almost everyone got to at least read all of the proofs.
Hilbert's Hotel 