Kitchen Commandment: She who cooks the dinner shall not clean up from dinner.
I don't want to raise any of you to take housework for granted. It's hard. It's unfair and not cool to expect anyone (parent, spouse, roommate, etc. )to wait on you.
Have them sort change, and eventually to count it. It teaches them to gather things that are alike, it's an introduction to money and it occupies them for 15 minutes! Just make sure they're old enough to be past the point of putting coins in their mouth.