I can't relate, because I have a DD9 who has declared the opposite: "I want to know EVERYTHING!"
It's hard to advise without more information. Is the problem that they're asking him math questions during lunch and recess? If this is the case, your DS could enforce proper boundaries. "I'm not doing math right now. Ask me later."
Are they asking him random questions, trying to get him to perform, or are they genuine questions? If the latter,
there can be a lot of cognitive and social benefits for helping others learn, and maybe your DS should be taught to embrace that, with proper boundaries. On the other hand, he should not be asked to do math like it's a performance for their amusement.
