Zach broke the ice with a proof involving semicircles. Soon afterward, however, so many kids were weighing in that they began to become a bit territorial. To make sure we knew who got dibs on what, we started an ownership board. (Don't read it too closely ... not all of our wishes came true.) The board not only reserved shapes for specific kids, but it also helped to accelerate a sort of arms race between the more competitive of the group.
And speaking of competitive, two of the kids who took Algebra 1 the previous year as seventh-graders had been getting pretty jealous of the class as the kids worked their way through 42b and the Rock Problem; if you see some new faces below, it's because the class finally took pity on Ben and Carl.
We shared this initial group of findings with Dr. Wiggins. Click any photo to enlarge it.