This activity kit challenges students to create a propeller-powered device that travels along a string. The essential pieces, propellers, rubber bands, and string, are provided; it’s up to the young scientists to determine the best materials to use in order to propel their racer effectively. Using the engineering design process students will create, evaluate, and redesign their simple machine until their objective is met. Includes enough materials to begin 6 racers. 38 pieces total.