My DS9 is a 4th grader and he also got 25 in math this year. His math teacher sent him to middle school class one hour a day for the semester. DS was invited to join the math team in middle school. After a couple of heartbroken experience in math contests with some of the best 7/8th graders, DS told me that EXPLORE was actually the easy one.

We are looking at a similar scenario this coming year, so I'd love some feedback on how it all worked. Did you son take a bus to the middle school? Did you transport him? How did it work with his other classes (the ones he was missing, or were you able to schedule it during math)? Will he need to do the same thing with the HS at the end of MS? How did the MS teachers and students react?
As far as the math team, ds10 also would like to join (ours isn't very good, lol, so there is no "invitation" - although the highest scoring students on the AMC get to be the official competitors). Can students who are not at the middle school officially be part of their team? Were the older kids on the team okay, or did they feel like he was "stealing" a spot?

It's great that he did so well on the EXPLORE! Will you be taking him to the NUMATS ceremony if he qualifies? Have you gone before?