You may not have time to do it all, so discuss your situation with members of the department. You might also take Mathematical Modeling, which is sometimes taught as Math 250. To become an actuary you need to pass a series of exams offered by the actuarial profession. You can take the first two exams as an undergraduate. These cover calculus, linear algebra, probability, and statistics.
Many insurance companies offer summer jobs for students interested in actuarial work.
For more information about actuaries and actuarial mathematics, see the career materials in the Department office. Wellesley's Computer Science major requires that you take at least one of these mathematics courses. You might also consider Graph Theory or Numerical Analysis, which are sometimes taught as Math 349. If you wish to take a 300-level course, consider 302 and 303. For more information about careers that use mathematics in management, see the career materials in the Department office.