Math fair game questions?

Question

our school is having a math fair and the 7 grade has to build games where each grade has a chance to win and it somehow has to do with probability (so if there's 2 prizes..large or small..u have to have a 50% chance of winning a large prize and a 50% chance of winning a small prize but if there's 3 prizes..small medium large...there has to be a 33% chance fo winning one of them) the game can't have anything to do with common sports like baseball, football, volleyball, or anything because the kids can play those anyday...if you have any ideas for a game please tell me (and remember a 7 grader has to be able to make it)...any questions please ask and i'll add details based on the question and if u do ask a question please check back later

Answer 1

They're just being ignorant.  You're better than that.  I just wouldn't play with them anymore.

Answer 2

You could have them draw a card and assign a value to the card.  For example, have cards numbered 1-10 and 1-5 gets a small prize, and 6-10 gets a large prize.

Or, have a washtub and put floatable objects (usually rubber ducks) with numbers on the bottom of them.