venice, my take on your particular situation is that your district is refusing the *acceleration* rather than refusing the outside test results and outside recommendations. Your ds clearly hit the 99th percentile on the MAP test done at school, so that in and of itself would probably have been sufficient if the district wanted to provide subject acceleration.
My recommendation is to try to network through the grapevine and find out whether or not there are other students who've been allowed to subject accelerate in math. What you need to find is one example of "it's been done" and then go back with a written request to your ds' school stating every test results and written recommendation you have.
Best wishes,
polarbear
