I have used Mistake Game a lot in class. Students write up the solution to problems on whiteboards and purposely make a mistake in the solution. Then they present their solutions to each other, presenting their mistake like they meant to do it. Then, students ask thoughtful questions to try to find the mistake.

This works great with topics that are conceptually rich, but less so in topics that are more mechanical, where mistakes tend to be a bit harder to see and are less rich to talk about, like implicit differentiation for example. I did a modification of the Mistake Game that worked really well for this:

1. In groups of 2-3, students write solutions to a problem on a large whiteboard. After checking their correct answer with me, they go back through and make a mistake in their solution.
2. Students then flip over the sheet I gave them that had their answer and write what there mistake is, kind of like a mini answer key.
3. Groups then rotate around the room and try to find the mistake in the solutions in front of them. Once they find the mistake and check their answer with what the group wrote, they move on to the next board.

I wanted to train them in the art of looking over a solution and checking its correctness, and I think that this did that well. Compared to the mistake game, I felt like more students were active at any moment, more students could carefully follow complicated work, and it took much less time (20 minutes as opposed to 40)… but we also didn’t have the great mathematical discussions that we normally have during mistake game. I guess it really depends on the topic at hand which version is more appropriate, so I’m definitely going to keep this one in my teaching toolbox.