Gears

Gears are special wheels with teeth around the edges. When two gears meet, their teeth fit together. One gear turns the other. Gears are used in all kinds of machines to make them work.

How Gears Work

When one gear turns, it makes the next gear turn too. If the gears are different sizes, they turn at different speeds. A small gear moves fast, and a big gear moves slower but with more power. Gears can also make things turn in the opposite direction. This is very useful in machines.

Gears in Machines

Gears are inside many things we use. A bicycle has gears that help you pedal up hills. Cars use gears to go fast or slow. Old clocks use lots of tiny gears to show the time. Wind-up toys, drills, and even electric mixers use gears to work.

Fun Facts

• Some clocks have hundreds of tiny gears inside them.
• The biggest gears in the world weigh as much as an elephant.
• A ten-speed bike has ten different gear settings.

Did You Know?

The ancient Greeks made a computer out of gears over 2,000 years ago to track the stars.