I've pretty much taken all the maths subjects (from the maths faculty) that actuaries take. It consists of 2 semesters of calculus (although one of which contains linear algebra), probability and statistics. Actuaries also take financial maths and other mathsy subjects which I know very little about.
As you may be aware, I was tossing between actuarial studies and maths, I chose maths and am rather happy with my decision so far. I imagine I'd be rather unhappy doing actuarial studies -- I have no passion for it. I'm sure actuaries learn plenty of difficult maths, and there are many tough problems in actuarial studies but I know it won't feel the same as in pure maths. Actuarial studies is like writing a letter whereas pure maths is closer to creating a poem. But then it's not for everyone.