有關美國SAT大學試

There are two different type of SAT test. The first one, SAT Reasoning Test, is required by almost all universities in the US (unless the school accepts ACT only, but it's rare). SAT Reasoning Test includes three areas -- 1, Reading, 2, Maths, and 3, Writing. So, no, Maths is not considered a subject test here. SAT Reasoning test is US$45

The second type of SAT is called SAT Subject Test (formerly called SAT II). Just like the name indicates, SAT Subject test offers test on different subjects for students to test and show their skills. Not all colleges requires SAT Subject Test, but University of California admission makes it mandatory for all high school applicants. Fees varies depending on subjects

For sample questions regarding SAT Reasoning and Subject tests, please see the following website from College Board.
http://sat.collegeboard.com/practice/sat-practice-questions.

Most universities count the best score in three tries. Regarding when to take SAT, you should check with the school(s) you plan on applying to, find out when is the application deadline, and then count backward. The website above will also give you a guildline on how to prepare for your application