Thanks all. They said some will be paper based and some computer based. So maybe a combination of things.
The person at the district said mastery was 85% but who knows if he scores that they would let him.
Part of me is worried that they will have extremely high criteria but do the testing as a way to say officially he doesn't qualify.
We haven't pushed at all for any extension or acceleration for him until now. I can't say he'll know everything he hasn't been taught but I do know that he is extremely bright and could learn anything they needed him to in a flash. They seemed to want to ensure he has all of the skills before allowing him to go to 4th.
Part of me wonders why they make it so difficult - they have a perfect cogat score, 151 on the wj and an IQ of 99.9 percentile. They have benchmarks that show he is at 5th grade. A perfect achievement report. And a teacher who has professed to do anything in her power to make sure he gets a plan in place to be challenged. On top of that he has good friends in the higher grade and a 1:1 shadow who would accompany him to the higher class and offered support with transitions etc. He is also highly motivated to do so.