What type of Math should I study for the SAT?

I took the PSAT and didn't do to well on the Math portion...and I get the SAT quesion of the day from collegeboard.com, and I do terrible on the math ones. I have a friend who's a foreign exchange student from China and he tries to help me with the math but I need to study much more this summer. If you can tell me what subjects I should study to do well on the Math portion of the SAT please do