After taking all of the practice tests in this book, I can honestly say that this is by far the worst test-prep book I've ever read (and, like most high schoolers, I've read quite a few.) The explanations and the questions are both broader in scope than anything that might be found in the actual test or a math class. The questions are hapazardly thrown in with no regard to difficulty, and the tests themselves seem to have no consistent difficulty levels (I scored 800 on one and barely 700 on another.) One exam, for example, had 2 or 3 questions testing the exact same concept, with slightly different numbers. Though the harder questions might have argueably given me an edge when I do the real SAT II test, they certainly did not merit my purchase.