That's also 4 entirely different curriculums which need to be taught. I volunteer taught CS for about 10 years, and the first year I taught a new class- and this was a single class for high school kids- I always found I was much better at it the second and third time around. I taught about 4 different courses, of varying difficulty- intro to programming with SNAP, "CS Principles" which had a little bit of everything from (very) basic networking to html and a bit of javascript, Javascript/Python, and then the final boss... AP CS in Java, which is a very difficult class.

I find it difficult to wrap my head around you can make it work teaching the entire curriculum for 4 different grades encompassing reading/writing, math, history, science, art, music, etc... I guess its potentially compensated for by the fact that they are all getting very individualized attention, but thats spreading a parent very thin.

Especially when we are talking about high school levels, where you can even potentially go into AP courses- no way a single parent can teach college level calculus, History, CS, etc... effectively.

For all the flaws of our public education system, I don't see how this can work better.