One of my favorite things about teaching middle school math is when students’ curiosity drives the lesson. It doesn’t always happen on its own; sometimes I need to create the conditions for wonder to bubble up. Over the years, I’ve leaned on two approaches that consistently spark inquiry: Which One Doesn’t Belong? and Show Me Your Math . Which One Doesn’t Belong? Inspired by Christopher Danielson’s books, this routine invites students to look at four numbers, shapes, or images and decide which one doesn’t belong. The beauty of this activity is that there isn’t just one right answer. In the image below, students might say that D doesn't belong because it's the only circle, while C doesn't belong because it's the only blue shape, and A doesn't belong because it's the only shape broken into thirds. Once students can find reasons why one item doesn't belong, you can challenge them to find a reason why each of the items doesn't belong. What I love about ...