One of the new Regents' requirements for students graduating under Semester System rules is that you must take at least 39 semester hours of upper division courses. Since the Mathematics Major requires only 24 semester hours of MATH courses, this means that you will need to find 15 additional hours of upper division classes.
Of course, there is no reason why some or all of these 15 hours cannot be in Mathematics -- you are certainly encouraged to take more than the required minimum hours in MATH.
To help you plan ahead and find other ways to satisfy this requirement, we have provided lists of math-related courses that have few (or no) non-MATH prerequisites . The College of Arts & Sciences also maintains a page of upper-division courses having at most one prerequisite .