For beginners, a good Olympic mathematics textbook must be very detailed, including all the knowledge points of primary school Olympic mathematics, from easy to difficult, not too complicated. There must also be "giving inferences." Every knowledge point has examples and exercises. Practice has both answers and explanations. After completing the examples, children can exercise and consolidate what they have learned in practice. Because in the study of Olympic Mathematics, if a child can't do a problem, it may bring a class of problems that can't be done. If there is no "extrapolate" approach, children can easily forget this knowledge point.