@3kids2dogs
Both my daughters were double majors with one of their majors being math/applied math. (Math/physics and Math/biological neuroscience) Both went to med school. The math degree plus a some exposure to computer programming opened all sorts of post-college job opportunities. D2 directly leveraged her math degree + research lab experience into a tailored just for her job (job description written so no other candidate would qualify for the position) at a top 10 medical school after college graduation.
The math degree also opened up the potential to pursue a variety of medicine-adjacent career pathways in grad school, including BME, epidemiology, biostatistics, bioinformatics, radiation therapy, health & medical physics–all well paying and in high demand careers. (So in demand, in fact, three of D2’s friends dropped out of their bio PhD programs to earn a MS/MPH in bio stats because the job market is so strong.)
Outside of medicine-adjacent careers, a BA/BS math degree can open doors for careers in finance & investing, risk management, insurance, engineering, biotechnology, software development and IT, engineering & technology, (D1 was offered a job w/ a major cell phone company doing calculations on how to optimize cell coverage & routing; another classmate went to work for a multi-state utility to help manage & optimize the electric grid; still another went to work for a major airline doing schedule optimization and the traveling salesman problem ), city planning and development, plus probably more I can’t even think of.
Med school adcomms are agnostic about what undergrad major an applicant has, though both philosophy/humanities and math majors do disproportionately well in med school admissions. (See–[MCAT and GPAs for Applicants and Matriculants to U.S. Medical Schools by Primary Undergraduate Major, 2018-2019]( https://www.aamc.org/download/321496/data/factstablea17.pdf)) Warning–[selection bias]( Selection bias - Wikipedia) is undoubtedly involved in the data.
D1 & D2 had classmates w/ all sort of “exotic” majors-- like agriculture (just finished her MD/PhD, matched into IM/research hepatology); sociology (pediatrician), Spanish (IM hospitalist), music theory (IM geriatrics), English lit (pediatric surgery) , theology (oncology).
Note: math and other “hard” majors do not get any slack from adcomms for having a lower than optimum GPA/sGPA. Your D still needs to excel academically, but math does offer better Plan B career options than bio or even chemistry does. Having a double major also gets no slack from adcomms, nor do adcomms find it impressive. Your D should do a double major only if it makes financial sense or is crucial to her alternative career plans.
RE; scheduling. D1 needed to complete a full math minor as co-req for her physics degree. A major meant adding 3 additional math classes–which she took over the summers since she was working at the university anyway. Because she didn’t decide to apply to med school until her senior year, she was missing ochem --which she took after graduation as a part-time student while working and getting her ECs in order.
D2 entered undergrad with math coursework through linear algebra (4 semesters of math major math) already completed during high school. She only needed 5 math classes to complete a major, 2 of which she “double dipped” (took classes that counted toward both majors). She had no issues whatsoever scheduling since all her pre-med requirements were included in her second major. She finished her double majors & all pre-reqs in 8 semesters.