You can also use "récréation" which literally means "recreation" and is used specifically for breaks in school.
Here are some examples:
* "C'est l'heure de la pause." (It's break time.)
* "On a une pause de 15 minutes." (We have a 15-minute break.)
* "Les élèves ont une récréation de 20 minutes." (The students have a 20-minute break.)