A gear is a wheel with teeth along the outer edge. By itself a gear cannot do much of anything. But in combination with other gears a lot of things can happen. Gears can transfer effort from one place to another. There are gears inside almost every machine, that connect the roatating parts.
Gears can change the direction of the rotating parts and can change the form of mechanical motion.
The best way to find out how gears work is to make some of your own to experiment with. Students will be able to identify what affect the position of their pen has on the drawing's outcome. Students will be able to gain an understanding of how a gear system works and be able to describe, verbally, what affect the gears have on each other when the system is in motion. Asking the students to describe a gear, giva a definition, and what gears do. Teacher will ask the students if they have used a spirograph.