One other note - it sounds like your ds is exceptionally gifted and he's clearly ahead academically at this point. I wouldn't necessarily put that forward to the person you talk to as "proof" of his IQ being exceptional, just let the person know this is where he's at re achievement at this point in time. You might think of some of the ideas your ds has had or some of the things he's done outside of academics that point to giftedness to mention.
I agree. It's probably best to be very concrete and keep things focused on your child and his educational needs. IOW, don't argue about how exceptional or otherwise he is; just make clear what he's doing now, and ask about how the school can ensure that he is challenged enough and keeps learning. I'd take a couple of the books he's reading for pleasure, something he's written, a page of sums that he's done for fun, or whatever seems appropriate, and use them in the meeting.
