@Ashley, thank you for your suggestions. We submitted all his achievements /certificates to 6 schools. Not sure if we need to do any extra to convince admission office that DD is a good candidate? Please suggest ...
As I mentioned earlier, a recommendation letter from the coach/instructor (need not be academic, could be in sports or music) that says in detail why your son is a great student will certainly help convince the admission committee in the new school. Also, make copies of work samples where your son has done remarkable work - showing his teacher comments appreciating his work (like 100% in a test with teacher writing positive feedback or AOPS work) will help. Make copies of the work and send them as additional documentation to the schools that you are hoping he gets into.
In my opinion, if he is going to do better in the new school due to more challenging school work, there is no harm in going the extra mile in providing all kinds of documentation. Good luck.
