My algebra 2 students needed more practice solving equations with rational exponents. I was trying to think of an interesting and yet still effective way for them to keep practicing, and then I thought about how the errors they make tend to be the same again and again. That reminded me that I hadn't done an error analysis activity in a long time - and just like that, the lesson was created. I assigned each table pair one problem, where they had to find the mistake, explain it, and do the work correctly. Then each pair was called to present their findings to the class; the class then worked out the problem and if they all agreed that they had found the correct solution, I allowed them to move on.
Students were generally good at finding the mistakes I had made. Will this activity help keep them from making the same mistakes in the future? We'll find out next week.
Here are the twelve problems plus homework.