The Secret Book of Learning Thinking is suitable for children who have stable grades, spare capacity in learning and want to improve their mathematical thinking ability. This kind of books are mainly aimed at those students who have excellent grades in school and seek extra training in mathematical thinking. The content is more difficult, suitable for students whose grades are in the top 60% of the class. The content is mainly aimed at the cultivation of mathematical thinking. The difficulty of this set of books is second only to the big white box, suitable for children with stable grades and above 95 points, and can be used for mathematical thinking training. Xuesi Cheats is a set of mathematics textbooks edited by Xuesi Teaching and Research Center and published by Modern Education Press. This set of textbooks aims to scientifically construct the knowledge system of all subjects according to the curriculum standards for junior and senior high schools promulgated by the Ministry of Education. The content is based on the textbook and higher than the textbook, covering all required knowledge points. The training courses and exercises including primary school mathematical thinking are divided into 12 grades, covering primary schools from 1 to grade 6, and each grade contains 20 topics.