Mathematics tools

Speaking of random quiz questions, how do you let Moodle know what the right answer is?

Also, is there a module that has random math questions created for quiz/exam?
What would be the closest module that creates math questions on the fly?

To clarify: I don't want to store any questions at all, but rather have code create them
dynamically, and score them once the quiz page is completed.

Im considering writing such a module and would like to know what module is a good place to start from.


Thanks,