When I picture great teaching, I see unconventional ways of learning math. The surface area of a sphere can be found by peeling an orange. Tracing the Great Circle made by a sphere, students discover that the peel of the orange (when cut into tiny pieces) perfectly fits into four of these circles. The ares of a circle is pi times the radius squared. Therefore, students discover that the surface area of a sphere is 4 times pi times radius squared. Learning is so much better when the students do it themselves, rather than have it given to them on a chalkboard!