The SAT II exams serve various purposes in college admissions. Many universities require them for admissions and they help show an applicant’s strength in one or two core subjects. Some schools use them for placement purposes to determine what level classes a student should take. It is best to send three SAT II exams as it fulfills the requirements for all major universities. You should start early in terms of the number of exams you take. The subject tests are similar in curriculum to the AP exams and therefore if you take an AP exam, you should look into a corresponding SAT II exam as well. You should try to take one exam your freshman year, two your sophomore year, and three you junior year. You can also take some exams your senior year, but it is best to avoid senior year exam taking unless you are confident you can do better in the fall. Taking exams every year of high school is beneficial because it shows your advanced skills in certain subjects earlier than the junior year sprawl of subject tests. There is no magical score here either, and so it is best to just work hard and send your top three scores. You should think about sending your scores even if your school doesn’t require them for admissions, because they can add another dimension to your application and aid in placement purposes.
These are some programs that are popular among high school students. This is by no means an exhaustive list of nationally recognized programs. Boy’s/Girls States