I think we could probably overhaul the education system in this country right at the root.
Advancement is tied to age and it happens just once per year. It's time to scrap that notion. Advancement should come at any time and at any age. If a child has the aptitude of a 2nd grader, but happens to be in 1st grade, move that child right then and there.
In addition, quit linking subjects as if their related. I can't see why a young student can't be working on 4th or 5th grade math while they're also working on 6th or 7th grade English.