Show HN: A Simple Math Quizzer

Hey all!

I built Math Factory a while back as a favor for my wife (who home-schools our children) to help quiz the kids on basic math facts. As such, it's very basic (I think I spent more time entering problem sets than building the site).

I'm trying to evaluate whether this is something I should iterate on or not, so consider this sort of like a demo.

Suggestions are welcome--I have some ideas, but I don't want to pollute the air. Thanks in advance.

Dave