Math courses are simple (when your professor does not give you a headache, haha). Pre-Calculus and Calculus are simple, the only problem is remembering those damn formulas, when to use them, what information to apply it and interpret application problems.
even then that has still not been a problem for me, if anything my only problem came from professors who were harsh graders. something as simple as a missing negative sign would warrant 15 points taken off your test to them