A compass is a small tool with a needle that turns. Hikers and sailors use it to find their way.
Key idea
A compass needle always swings to point north. Turn the compass until the N lines up with the needle. Then every letter on the dial points the right way.
Why it works
The needle is a tiny magnet. Earth acts like a giant magnet too, and it pulls the needle so that one end points north. That is why the needle swings back, no matter how you turn.
Worked example: Finding west
The needle points at a big tree. Which way is west?
- The needle points north, so the tree is north.
- Face the tree. West is on your left.
Answer: To your left.
Common mistake
Some children think the needle points the way they are walking. It does not: it always points north. First line up the N with the needle, then read the direction you want.
For the grown-up. A phone compass app works for practice. Older children may like to know that a compass points to magnetic north, which in most places is close to, but not exactly, true north. Magnets and some metal things can pull the needle off, so hold it away from them.