Today my students completed 2 "mystery bag" activities. These activities are designed to provide a contextual understanding of solving equations. I have used an activity that used the idea of using a balance before but there wasn't a story to go with it. Once again I believe the context helped my students to grasp hold of the concept. Supposedly my students learned how to solve all types of equations last year. I could definitely tell that they were better at solving equations than previous years. However, I retaught solving equations before we started our new books.
The IMP Mystery Bag activities assumes that students have already been exposed to solving equations. Doing this activity makes me wonder how many times it takes our students to see a topic for them to retain it.