Pre-Data Theory students are not required to take Math 33B in order to declare the major, and Math 42 is sufficient for any upper division courses that list Math 33B as a prerequisite.
For any upper division math courses with a Math 33B prerequisite, students can bypass MyUCLA's warning message and enroll anyway if they are currently In Progress or have already completed Math 42. The Mathematics Department will not drop them if they skipped Math 33B.