How impressive and how much will it impact admissions if you take college level courses like calculus 3 while in high school. I’m not able to take calculus 3, but I am thinking of taking a microbiology course at my local community college, yet I don’t know if admissions will really care that much about it.
Also I know a freshman interested in computer science and they want to take computer science classes at our local community college. If they were to somehow take all 5 computer science classes before they graduate, that would be equivalent of UC Berkley’s CS 61A, 61B, and 61C which meets their lower division CS requirements. Now I don’t know if they would be able to take all the courses to get past 61A-requires 2 colleges CS courses-let alone if all the courses would even transfer, but if they did would that be impressive to colleges? Is it even worth spending your summer to do that, or would colleges rather see summer programs such as hackathons or what-have-you?
Colleges don’t care if you took calc 3 or microbiology while in HS, per se. They do care that you have a valid math and science sequence, and that you take the next course in the sequence. If you run out of options in HS, then looking for options at a local college is a fine choice, but there is no reason to accelerate the curriculum to do so.
The danger of taking courses over the summer, as opposed to any other activity, is that one risks as being perceived as a one-dimensional academic grind.
I don’t think it’s worth using a summer to take courses at all. It’s one thing to take CC courses because you’ve exhausted your school’s options during the school year, it’s quite another to use your summer just to try to get a perceived leg up.
IMO, you are much better off using your summer to get a job, volunteer, etc…