For comparison our DS7 (>99.9 in Math on the WJ-III(ach.)) is half way through grade 6, (and is finding it pretty easy) and will also complete grade 7 this school year. This is possible because we are using a virtual school.
With similar scores (>99.9 means top 0.05%), your DS7 may be capable of the same level, or could have been if he was allowed to accelerate. A single year acceleration is woefully inadequate.
He was getting some pull-out one-on-one enrichment but that person said he has trouble with focus after a few minutes and that he didn't want to do things he didn't understand. (The latter is one of our biggest fears for him... that he will back away instead of digging in, when there is a challenge.)
That's certainly not good. It is important to rise to a challenge.
The teacher seems to think just being in that class is enough enrichment. And... has already mentioned focus and slight behavior problems, along with it being very important to know how he is getting to the answers (had another thread on this, he's playing along well now with writing down how he solved problems).
This type of "showing work" at this level is just ritualized busywork. It is a complete waste of time, and has no educational value.