Teacher helps fit the ball into the clamp. You want it to be secure, but don't squish the sides in or the planet will be flat. Stand behind the child, show him or her how to hold the saw. They should use 2 hands so there is no danger of them cutting themselves. Cut the ball in two equal-ish halves.
Teacher holds the ball steady with one hand by pushing down of the very edge by the clamp.
Your other hand will be holding the saw. Most have no trouble, some need help getting started. Glue the half ball to the center of each circle. Decorate your planet with paint or squeeze glue over both halves and cover with glitter or sand. The glue leaves a nice track, some painted the glue on and had a smooth finish.