Both those countries are also very prosperous and innovative. It seems the people or culture are what makes them do so well not the amount of school hours.

For all we know parents in those countries are far more supportive of their children. And may also be intelligent enough to assist their children with the homework. By intelligent I mean they are able to teach their children well I don't mean to be able to understand what a six year-old is learning (if not there is a far bigger problem!).