Yes, do brush up on your math skills. Do not try to cram in a whole bunch of knowledge in the sciences- these entrance exams are not knowledge based but consist mainly of critical thinking questions in the science area. I feel like for the science and english...you wither know this stuff or you don't, but you definitely should brush up on basic math skills. For my entrance exam, you had to pass the math portion with an 80% or better or they *strongly suggested* you take a summer pharm calc prep class. I got a 79% and while the prep class wasn't required, I did take it, and I ended up being SOOO glad I did, because when the actual class started, 26 of my classmates were lost and clueless, while the 4 of us who took the summer prep class had a much easier time.
Moral of the story: no matter what your math score is on the test, if there's a preliminary prep class offered, take it.