Dude sriously, it's not that simple. You don't just make them, "tadah wooo we have a game!" There are lots of different jobs that require specific training and background. Do some research.
I suggest: http://www.blitzgames.com/gameon/index.htm
and also http://www.gamesindustry.biz for job listings as far as testing goes.
Honestly you need to decide which part of the team you want to be. But maths will probably be needed in all of them so DO IT. I think more people could do with A-level maths anyway.