UCLA is probably better overall for math, but UCSD is better for graph theory and combinatorics in general, the most likely kind of math CS students would be interested in.
In my opinion, there will be very little difference between the schools in terms of education, quality of peers, or job potential upon graduation. I would choose based on which location I like better. Personally, I hate LA, although UCLA's campus is beautiful. There's probably a lot more to do there, too, depending on what activities he enjoys.
UCSD has a great zoo, Sea World, and Lego Land nearby, but not much for drinking establishments. Many CS and math majors go to the pub on campus regularly; I haven't heard of anything else.
Downtown San Diego is a long trip for nightlife. Most students probably won't have a car (parking is ~$600), so it'll be over an hour on the 30 each way (150 doesn't run at night). I don't even know how to get to PB by bus. My friends who live there all drive or bike to school.
UCLA is probably better overall for math, but UCSD is better for graph theory and combinatorics in general, the most likely kind of math CS students would be interested in.
In my opinion, there will be very little difference between the schools in terms of education, quality of peers, or job potential upon graduation. I would choose based on which location I like better. Personally, I hate LA, although UCLA's campus is beautiful. There's probably a lot more to do there, too, depending on what activities he enjoys.
UCSD has a great zoo, Sea World, and Lego Land nearby, but not much for drinking establishments. Many CS and math majors go to the pub on campus regularly; I haven't heard of anything else.