I confirm this! My son is 10, finishing 4th class. We're constantly 6-9 months ahead of his class. I think he once in those 4 years got note 2 (one below highest), every other one was the highest. Vast majority of his math classes look like "oh I know that" or "oh I remember that, just need a 5 min refresher". Thanks to it, he has more time for other subjects. His stress level at school is close to zero.