Ok so I’m a junior in high school and I really need to get in these SAT subject tests. Last year I took the chemistry SAT test and im didn’t prep at all 
so I got a 620. But this year I plan on taking US History, Math II, and Biology. Is it really necessary to take all 3? Because I’m already taking my SAT I on May 2 and the only date that won’t be too early would be June 6. I would have to take all 3 subject tests on one day. Also, how should I study for them? I’m taking the APUSH and AP Bio exam in May and I plan on purchasing prep books for them. Would it be enough to just prep for the AP exam for the SAT subjects? I don’t want to buy another 3 prep books for the SAT IIs that I probably won’t even have time since I’ll be preparing for the AP exams. Thanks so much in advance!!
Bump
I would advise studying thoroughly for the AP exams, and following the AP exams borrow SAT subject books from the library or friends and taking practice tests (you don’t have to re-study the material if you do well, just lightly review). For math 2, I advise having a Ti-nspire as it really helps and taking lots of practice tests.