It is reasonable to study mathematics in advance in the fourth grade. It's good to learn math in advance. Nowadays, the competition is more and more fierce. If children want to surpass others, they should be one step ahead of others, learn mathematics in advance, so that children can know the outline of knowledge, so that they can check and fill in the gaps when studying at school and save more time to do other things. Otherwise, the later, the more children see the gap with others, the more anxious they will be and the situation will get worse.