We are building a wigwam in our playground as part of our fall Native American unit. Teachers cut down poplar branches on a family's property and then, with the children's help, built an authentic frame for a small wigwam. We will cover it with birch bark harvested from dead birch trees on another family's property. The children learned mathematics while they were helping build the wigwam frame--they estimated, measured, added, subtracted, and divided. The close-up picture below shows the students working with their tape measure.