I don't know anything about your school, but the math on the SAT is like our 8th and 9th grade math. The math isn't very difficult on the SATs.
I don't know if you are able to do this, but my parents contacted the school and asked for the name of a good math tutor outside the highschool. It turned out to be one of the teachers in the school, the same teacher that tutored my boyfriend. He was amazing, and within weeks my practice scores jumped from 500 in math to 700 by the end of the sessions. I really understood the material.
This is also helpful because the SAT math section has many tricks to it that make the problems easier and quicker, saving time for the more difficult questions. There are certain types of problems that always appear, and once you learn them you realize that the problem is the same problem you did at home with different numbers.
My school also offered a class called "SAT prep", which some kids took. Almost every friend of mine hired tutors that came once a week, one for math and one for verbal.
Our local Y also offered SAT review classes.