Squigly Squigly's Brain Teasers

Question:

In division, the numeral the dividend is divided by is called...what?

Answer:

The divisor.

Try another Brain Teaser:

It's so strong, it does not break,
It's so powerful, it penetrates a lake,
Sometimes it's weak as a twig left out in the sun,
It's so wonderful it gives us the power to have fun.
What is it?