Hi newyork2012,
Many Test Takers are a bit 'rusty' on some of the Quant/Verbal subjects that appear on the GMAT, so you are not alone. Thankfully, there are a limited number of subjects that you'll see on Test Day, so you CAN train to properly face them all. It's worth noting that the Quant section of the GMAT is NOT a 'math test'; it's a critical thinking test that requires lots of little calculations as you work through it. To score at a significantly higher level in the Quant section (and thus, overall), while you'll certainly need the essential math knowledge and the ability to do math 'by hand', you'll also need to become more of a strategist - and change how you "see" (and respond to) that section of the Test.
Before I can offer you any additional advice about how you might proceed with your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied?
2) What study materials have you used so far?
3) How have you scored on EACH of your CATs (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) What is your goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School?
7) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich