When I picture great teaching I see students working collaboratively, asking questions, testing their ideas, researching their thoughts while their teacher guides and supports their work. These students were trying to make a figure that had the greatest surface area. They were given a sheet of poster-board and tape. When they asked, they could get different tools, like a ruler, meter stick, compass, etc. When a teacher lets students explore, they are creating learners, not just students. The more a student can investigate and try things for themselves, the more they are learning and making connections. That is what great teaching looks like.