Both have competitive admission to get into CS. Do you have other admissions to the CS major, or where getting into the major is not difficult? If you attend one of these schools, would you settle for a different major or transfer to a less selective school for the CS major if you do not get into the CS major?
Math graduates do often go into finance, actuarial, or computing jobs, or continue to teacher credential programs. Appropriate electives are desirable or necessary.