Construct and explain 5 simple machines to explore effort, force, load, motion and distance. 63-piece set allows students to simultaneously build a lever, pulley, inclined plane, wheel and axle, and wedge, then modify the machines with 4 weights (two 5 g and two 10 g) and 8 rubber bands, all included. Labelled pieces assemble easily and separate to store. With an illustrated activity guide.