Mathematics at least in the U.S. is what they call "Spiral" in nature. Many years like 1st/2nd it is mostly the same topics, but each year just a bit more "difficult" ie.. adding number up to 100 and then the next year to 1000. I think this may work for many kids to get mastery in the long run, go back review what you learned last year and take it a bit further. But for kids who are gifted in math this is simply frustrating, repetitive and unnecessary.