He has certainly not "mastered" the grade 5 curriculum, so I wouldn't see acceleration as a solution. ...
And I'm sad to say that the grade 6 curriculum looks very similar to grade 5.
How much repeat of 5th grade will there be in 6th grade? Maybe your standard of mastery isn't realistic? Maybe the school sees it as a 'process?' to be repeated over and over?
It hard because the elementary school years are all about 'can you do this? how about this?' - abstract thinking is believed to start about 6th/7th grade - and slowly at that.
Is there a way to compact the curriculum, so he can fulfill the requirements quickly and have more time for 'independent study?'
Are there alternative schools available?
Is homeschooling a possibility? Online schooling at home? Online schooling at school?
Tests like MAP are great for seeing what his true readiness level is. Try signing up as a homeschooler.
Good luck,
Grinity
