When I discuss plate movement in my volcano unit, I do a hands-on activity that gives the students visuals and a tasty treat. I give each child a piece of wax paper with a tablespoon of frosting on it and a graham cracker. The students break their graham crackers into segments. They put two segments on the frosting and move them like the plates of a volcano move. After the discussion, let the kids eat their plates. The students love this lesson, and it adds variety and visuals to a sometimes complicated lesson.