I think our district has 10 to 20% of 7th graders taking Algebra I. And there are always a few 5th graders bussed to the middle school for math, always a few middle school kids bussed to the HS for math, and always at least a couple of 8th/9th graders who ran out of math and take courses at a nearby university.
If they bus him to the HS for math, make sure it is for the honors (or highest level) of that course. You need to be in the highest math track in our district for the bussing thing to happen. This also ensures that the HS kids don't pick on him - other gifted/high achiever kids typically won't make him feel uncomfortable.
