Simple Machines Background Information for Teachers and Parents

Grade Levels: K-3

This page contains information to support educators and families in teaching K-3 students about simple machines. The information is designed to complement the BrainPOP Jr. movie Simple Machines. It explains the type of content covered in the movie, provides ideas for how teachers and parents can develop related understandings, and suggests how other BrainPOP Jr. resources can be used to scaffold and extend student learning.

In this movie, children will learn that a simple machine is a tool that uses force to make work easier. A ramp, lever, pulley, and a wheel and axle are examples of simple machines. Discuss with children how they use machines to make work easier. You may want to identify machines children use often such as a bus, a stapler, or a bike. While machines can have many moving parts, a simple machine has none or very few moving parts.

Explain to children that a force is a push or pull that can change the way something moves. For example, when you throw a ball you use a force to make it move. When you catch a ball, you use a force to stop its motion. Any push or pull is a force. Review with children that heavier objects require more force to move. For example, a bowling ball is harder to throw than a table tennis ball. Some objects are so heavy that people need machines to use them. A simple machine can change the direction or significance of a force in different ways to make work easier. It can change the way a force is used to make it more effective.

A ramp, or inclined plane, is a simple machine with a slanted surface. It helps people and things move between higher and lower places. Discuss different ramps children have seen or used, such as moving ramps, disabled accessibility ramps, or slides on the playground. Explain that it takes a lot of force to lift and move something heavy, but it’s much easier to push it up a ramp. It is much harder to move things up steeper ramps, or ramps that go up higher, just as it is harder for people to walk up a bigger or steeper hill.

A lever is a simple machine that consists of a bar that rests on a fulcrum, or a point that does not move. A lever can also help lift up heavy loads. A seesaw is the classic example of a lever. When force is applied to one side and is pushed down, the other side lifts up. Any tool that pries something loose is a lever, like the claw side of a hammer or a bottle opener. Scissors and staplers are common items that use levers.

A wheel and axle work together to make a simple machine. Explain that a wheel turns around a rod, called an axle. A wheel and axle can help move things faster or more easily, and also help things turn. Carts, skateboards, roller skates, bikes, and cars all use wheels and axles. Explain that heavy things can be difficult to push across a surface and can require a lot of force. But, if you add wheels to the bottom, it becomes much easier. Wheels and axles can act as fulcrums, as well. A wheelbarrow can lift and carry very heavy items using wheels as rotating fulcrum points. Have children give examples of how wheels and axles make work easier.

A pulley is a simple machine that has a rope or cable that goes over a wheel. A pulley helps people lift things up and change the direction of their force. You pull on a rope to make the load go up. You can also connect pulleys together, creating a combined pulley that requires less than half the force otherwise needed to lift up a load. Clotheslines, flagpoles, and blinds use pulleys.

Help children understand that combining simple machines can also make work easier. Any two or more simple machines put together are known as compound machines. Many machines are compound machines. For example, a crane uses levers, wheels and axles, and many pulleys to lift up heavy objects. Learning about simple machines and forces is a great way to teach the fundamentals of physics and help children understand the world around them.