Personally, I think it is necessary to study in private schools to take the exam or not. There is nothing wrong with letting children have a deeper understanding. Knowledge is private and public, and they can't study for exams. Learning is a long process, and difficult topics can lay a solid foundation for the future. The key point is that you can actually think backwards. The original intention of doing difficult problems is not to test children, but to understand children's level and ability through test questions and carry out targeted teaching. Don't have too much pressure, hope to adopt.