<p>I'm planning on taking chem, bio, and math 2 all in October. Should I start studying now, or a month or two before so the info will be fresh?</p>
<p>I can’t speak for biology, but I started studying for chemistry and math 2 about two weeks before the test, and I did well. If you’ve taken the classes at school then you shouldn’t need to spend more than a month studying.</p>
<p>It really depends on your current standing on these subjects. My D only spend one week to prepare for the Math2 and Chem subject tests after her finals at school. She took AP Chem this year and Math does not need much practice for her. By October, you will be at least a few months after you took the classes on Chem and Bio. It will take a lot more time for you to review. You should probably start a couple months before the test.</p>