I would caution against sounding like you know what it’s like to practice medicine. I have a degree in math, and it was a very popular point of discussion in all my interviews. People seem to think anyone who gets a math degree is really smart, and I heard from almost every interviewer I had that they wanted to ask me about my math research but wouldn’t be able to understand it. It always had a “that’s so cool that you know math” connotation.
But I also didn’t include anything about it in extra info. I included my capstone project as an experience and that was it. Writing about how my math degree would help me do something I’ve never done seemed like it might be a little presumptuous.
Honestly, the math degree helps a little in med school. I don’t really have to study for any of the stats or journal club stuff. The ability to think abstractly really helped during CPR which had the most math and most abstract concepts (looking at you acid base pathology), and pattern recognition has been tremendously helpful in clinical reasoning exercises.
But other than that, med school is largely just memorizing tons and tons of info, which is kind of the opposite of a math degree. So while it does help, I don’t think that the math degree itself is particularly super useful but rather that since a math degree is hard, if you can do well in a math major then you can handle med school.