This week's 3's test, he missed 3 problems. One he didn't get to (ran out of time), 2 he made mistakes. If I quiz him on the same problems at home, he gets the right.
I talked to the school principal and a parent of older kids. Principal explained the system- it's a rubric of scores, MAP, math facts, grades, teacher recommendation. If he doesn't have the math facts he can still accelerate into adv. 4th math based on the other things.
In order to go into advanced 5th math he has to have a requisite cog score, which he does, and pass a 4th grade material exam with ~80% knowledge of the 4th garden curriculum. He will be able to do that no problem. He is strongly self-motivated to accelerate in math.
The parent I spoke to (with four older gifted kids) said she often saw her kids suddenly self motivate to get faster at math facts around 6th grade when they start factoring. She has a kid similar to DS who is in his class right now, who scores high on cog tests but is still dorking around on the subtraction times tests, lol.
I also found out the other program that starts in 4th is the gifted language arts class. His previous scores are borderline, and it's a hard cap at 20 kids, so we just have to see how the scores shake out with other kids in his grade, and see if he wants to do the harder work.