All five regular polyhedra are built along with many truncated polyhedra. Now students have a basis for looking at objects in their world and relating them to the various solid shapes. Simultaneously, super-saturated solutions are being prepared for growing crystals. Students observe the development of crystals and relate these formations again to their polyhedra. Salt produces a cubic crystal.
Sugar crystals can take shape of hexahedrons or tetrahedrons.
Boric acid makes a triangular crystal. Alum crystals have an octahedral formation. As students blow bubbles, they see the basic ideas of geometric points, line and shapes, and bubbles which are not total spheres. They observe the patterns the bubbles are taking and the polyhedra they are making. Using pipe cleaners, they make skeletal models of the polyhedra edges which they dip in the bubble solution.