Levers are useful when we want to move heavy things.
Cavemen used levers to move rocks in front of their caves at night.
We wondered how they got inside when they got the rock in front of their caves!
A lid on a jar is a lever.
The handles on your bike are levers.
Archimedes said,
"Give me a lever and a place to stand and I will lift the world!"
We couldn't think where that would be!
