But personally, I don't think it is necessary. The knowledge started in junior high school is well connected with the primary school itself, and the transition is relatively smooth. Children can't understand and learn as long as they listen carefully in class. If children have time, I think it is a good choice to teach themselves in advance. Borrow some junior high school textbooks from neighbors and let them study by themselves during holidays and after school. The adults who can't help but give some guidance not only exercise the children's autonomous learning ability, but also increase the communication between parents and children, killing two birds with one stone. After all, parents are the best teachers for children.