The AP Calculus AB exam covers functions, graphs, limits, derivatives and integrals. In 2013, over 282,000 students took the exam. The mean score was 2.82.Most colleges and universities have a math or quantitative reasoning requirement, so a high score on the AP Calculus AB exam will sometimes fulfill this requirement.he AP Calculus AB exam covers functions, graphs, limits, derivatives and integrals. In 2013, over 282,000 students took the exam. The mean score was 2.82.