Using the two activity cards, students build a merry-go-round and a fan. Both models demonstrate how gears can multiply speed. By counting the number of turns and rotations, students can calculate the gear ratios. Gears Mini Set is designed to be used by students working in pairs. It includes:* 2 building cards with step-by-step instructions * Sturdy plastic storage case with clear compartmentalized tray * Pictorial parts list to make clean-up and inventory simple. 'Gears Class Pack' This pack contains enough materials for 24 students (working in pairs) to discover the basic principles of gears. Includes:* 12 Gears Mini Sets (779610) each with its own plastic storage case * 20-page Gears Teacher Guide (779620) 'Gears Teacher Guide' This 20-page guide contains 10 lesson plans, introductory gear activities, and problem-solving activities based on gear concepts. Also contains:* Photographs of real world gear devices * Background information * Suggested problem solutions * Assessment ideas.