Hard to pin down the variations between knowledge, gaps, direct teaching, and personal learning for any particular period. So for DS8.5:
math
pre 5 - ->G2
Age 5 - G1-3
Age 6 - G4&5
Age 7 - G6&7
Age 8 - algebra+?
That's functionally self-directed learning with some minor gap fills in school this past year. It is hard to ponder what it would look like with direct at challenge level instruction rather than time split at school between with I-dotting and T-crossing and doing his own thing.
Reading
pre-5 -> G2
5 -> G3
6 -> G4
7 -> G5-6
8 -> G7
Here the instruction is more tight but his placement is advanced but not accelerated as math is.
Science is such an unknown (heh.) Breadth and depth and variety are so many factors, I don't know that you can equate say having a two month astronomy segment in third grade to any particular curriculum or pace. Personal opinion is this would look best with wide sweeps of a variety of topics and deep-diving on demand until topic exhaustion. One day DS is watching random mainstream science videos and the next he spends three hours watching open courseware college biology 101 videos on cells.
