<p>He is “not good at math” but he is two grade levels ahead in math (reaching calculus as a high school junior after a sequence of honors math courses)?</p>
<p>Looks like your school has a two year calculus program, where a year of freshman calculus is spread over two years (AB ~= first semester, rest of BC ~= second semester).</p>
<p>If he may do a major that requires a full year of freshman calculus (e.g. economics, business, or any science including biology), he may want to take the rest of BC as a high school senior and possibly fulfill the freshman calculus requirement for his major with AP credit, instead of having to take a full speed second semester freshman calculus course in college. (Alternatively, if the AP credit is not accepted for some reason, perhaps due to not doing that well on the AP test, having seen the material before may help him if he has to take it again in college at full speed.)</p>
<p>On the other hand, calculus AB should be plenty sufficient for humanities or most other social studies majors (including psychology and sociology) at most colleges, unless there is a school-wide requirement for more advanced math (e.g. at places like MIT). Social studies majors should strongly consider taking a statistics course in high school and/or college (basic knowledge of calculus from calculus AB may allow taking a course that uses calculus for somewhat better understanding).</p>