<p>This depends on how the curriculum at your school is structured, but your son is on track to take AP Calculus his senior year - the usual sequence is Algebra 2, Pre-Calculus, and then AP Calculus. It is probably not necessary to “catch up,” though if that’s something your son wants to do, that is not unreasonable. You’re probably best off talking to people at your son’s school about this, but it is common to take a class over the summer, or to take two classes in one year, with each class taking two periods in one semester. I would personally recommend taking Algebra 2 over the summer, since I found that class quite useless, but this all really depends on what your son’s school will let you do.</p>