What is circumference?

Circumference is the distance around something that’s round, like a circle or a wheel.

Imagine you have a toy car, and it has big wheels. If you take one of those wheels and roll it on the floor, the path it makes as it goes all the way around is its circumference, just like how your foot moves when you walk in a circle!

Think about a hula hoop. If you want to know how long the edge of the hula hoop is, you could wrap a piece of string all the way around it and then measure that string with a ruler. That measurement would be the circumference of the hula hoop.

If you divide the circumference by the diameter (the distance across the circle), you always get a special number called pi, which is about 3.14, and it helps us find the circumference if we know the diameter or radius!