The SAT Reasoning and Subject Tests are taken by high school juniors and seniors. Scores are used as part of the college admissions process. The SAT Reasoning Test includes questions on critical reading, writing and mathematics, while the SAT Subject Tests are specific to their particular subject. The test takes about five hours to complete. To learn more about the exams and preparation, read The Guide to the SAT Reasoning and Subject Tests and our Interview with Karl Schellscheidt, SAT test prep expert.