Explains the challenges that face our planet as trash continues to build up, and teaches the importance of reducing, reusing, and recycling items in order to reduce the amount of waste produced.

"Machines help make work easier, like when you need to lift something heavy or reach way up high. There are six simple machines: the lever, the wheel and axle, the pulley, the ramp, the wedge, and the screw. Can you adjust a seesaw to lift an elephant? What happens when you combine two or more simple machines? Read and find out!"Amazon website.