I am also annoyed at the local school system, and full of foreboding about my son's initial teacher. The way that they apparently do things in the local school district is to assess all candidates for a grade skip in the first two weeks of school, and a multi-disciplinary team then issues a recommendation within a week or so after that, after which the skip may be accomplished.
This has benefits, I suppose, including relying on many different assessments of people within the system who have different types of experience, instead of heavily relying on just one assessment by a school psychologist. The more people on the team, too, the less weight a single teacher's recommendation will carry, helpful in the case of a skeptical teacher. A child is also assessed interacting with others and learning in a school environment, which might give a better idea of how he will actually function socially and academically if skipped. But there are also obvious drawbacks.
In my case, the school system seems so-so and the teacher seems to be openly skeptical that a grade skip would ever be useful. I'd rather be in your situation.
The "no assignments are permanent" bit makes me wonder if something similar is planned for your son.
I don't mind him working below his level a lot of the time becasue his writing skills are weak and I feel like this is an opporuntiy to concentrate on that.
I think that's a good way to view the 20-day period. I wouldn't worry about him being behind on the material, since he is a fast learner and the beginning material is probably going to contain a lot of review and at the most quite basic new stuff.
I think bringing specific information on achievement level is a good idea. You could also do a cheap online assessment, which might help:
http://www.letsgolearn.com/lglsite/DOMA_Basic_Math_Skills/parents/I would also ask for the materials from the accelerated classes, so that he can at least work through the workbooks etc. and doesn't get far behind, if you continue to be worried about that.
