My children can develop from grade one to grade five this year and get good grades. In the sixth grade, at the request of the math teacher, she began to learn math olympiad. Personally, I think math olympiad is very difficult for parents and children. Personal experience: If your child is not very good, don't try to squeeze the Olympics. If you have the ability to send your children to the school system, don't squeeze the Olympics. Personal opinion, for reference only.