Whether we know it or not, we rely on mechanical advantage from simple machines every day. Students will appreciate the impact of simple machines on their lives after building 60 working models of levers, wedges, pulleys, screws, inclined planes, and more. They’ll investigate how simple machines can multiply or reduce force, increase or decrease speed, and even convert one type of motion into another. Easy-to-follow build instructions ensure models are accurate when complete, and experiential activities allow students to ask questions and acquire their own answers by thinking critically and testing theories. Build instructions include explanations of scientific principles to supplement hands-on learning. Elementary and up. CHOKING HAZARD (1). Not for under 3 yrs.