What math class comes after algebra 2?

The courses you can take really depend in the High School you are in (I will assume that you are referring to High School Courses). After algebra, most schools allow Pre Calculus. Pre Calculus is basically just like algebra two, just with more trigonometry and deeper exploration of math. Then, one can take the flower of math, Calculus. In schools that offer Advance Placement (AP) courses, will offer AP Calculus AB and AP Calculus BC. Calculus was divided into parts, here A, B and C. I have heard of a D section, but is not taught in many high schools. Separate from the Calculus course tree we have statistics. One can take statistics, followed by AP Stats. (One might be able to skip statistics should they be competent enough for AP Stats.) There is also a branch of Math called Discrete Mathematics, that concerns mostly on logic, that is separate from other math course tree.There could be other math courses, such as Further Mathematics, but the courses stated above are the most common courses offered.