I have heard of the two most famous ones. Common ground: They are not detailed, just a set of formulas. Difference: there are many students, and there are teachers from relevant schools in the question bank. If you want to choose a school, you should prepare a lot of time and money. There are few people in Shandong.

Tell the truth: most children are really not suitable for learning Olympic mathematics. It's better to find a small class and learn some interesting math or something. From the results, you will know that most children spend 35 minutes, which means that these children don't need to learn this thing, just learn the knowledge of the school solidly. Olympiad is just a math game for a few people. Don't impose it on our children.