From a gear box to a helicopter, real-world examples introduce students to the importance of gears in the world around them. While building 12 models, they discover how to use gears to reduce/increase speed, adjust the amount of force exerted, and transfer motion. Introduce worm gears to show students how they affect rotational speed. Students also learn how screws convert rotational motion into linear motion. Easy-to-follow instructions guide students through the building process and explain how experiments correlate to scientific principles. Kit includes 151 pieces. Recommended for Elementary and up.