[5revive]

speaking from personal experience, the math I learned up to grade 4 in the Soviet Union was enough to glide through all of American high school math. And I wasn't in any way an advanced math student in the USSR. And I dont seem to recall any extensive, South Korean style homework.

[freepor]

You are probably really gifted. I don't think this is a typical experience, that a fourth grader in any country who doesn't do much homework knows most of US high school math.

[5revive]

In my Soviet school, we went up to Grade 10 US high school math and I have a clear memory when my old knowledge stopped and I had to actually learn. Up to that point it really did feel like just redoing old classes again.