Easy-to-build catapults for students in third grade include pencil catapults, plastic spoon catapults and catapults built with craft sticks. Use dowel rods for larger catapults.
Pencil catapults require two pencils taped together in a T-shape, with the horizontal pencil inserted across the width of a shoebox. Plastic spoon catapults can be constructed with plastic spoons, craft sticks and a paper clip. Remove the spoon and replace it with a medicine cup or small lid to create a simple craft stick catapult. Use 12 dowel rods to construct a larger, Medieval style catapult. Rubber bands or masking tape are used to hold simple catapults together.