[musicale]

Official grade level material for math and English in US primary schools is pretty basic. I spent a couple of weeks per grade on the math workbooks and absorbed English primarily by reading books (usually fiction borrowed from the school or public library.) Spelling drills might have helped with spelling. Handwriting exercises did nothing until I discovered (beautiful) cursive italic some years later.

I think you're right that public education is intended to provide a basic useful level of education to everyone. This is a good goal, though I think many students would benefit from asynchronous (vs. lock-step) study and a less rigid grade structure.