Wheels and Axles

A wheel and axle is one of the most important simple machines ever made. It has a round wheel that spins around a rod called an axle. Wheels help us move heavy things without dragging them. They make travel and work much easier.

A Great Invention

The wheel was invented about 5,500 years ago. Before wheels, people had to carry everything or drag it on the ground. With wheels, heavy loads could roll easily. The wheel changed the whole world. It is one of the greatest ideas in history.

Wheels in Action

Wheels and axles are used in countless things. Cars, bikes, buses, and trains all roll on wheels. A door knob is a small wheel and axle that opens doors. Steering wheels help drivers turn cars. Even a pizza cutter has a wheel and axle that rolls through the cheese.

Fun Facts

• The first wheels were used for making pottery, not for carts.
• A Ferris wheel is a giant wheel and axle that people ride.
• Some roller skates have wheels that spin thousands of times a minute.

Did You Know?

Turning the outer wheel makes the axle move with more force, which is why a big steering wheel is easier to turn than a small one.