In recent years, the "equation", "function" and "linear type" of junior high school mathematics have been the key contents of the senior high school entrance examination. "Equation Thought" and "Function Thought" run through the examination paper. In addition, "dynamic inquiry questions", "scheme design" and "hands-on operation" are also hot topics in the senior high school entrance examination in recent years. Most of these questions come from textbooks, and some have different knowledge requirements, but the questions are novel and the background is complex, so it is difficult to sort them out. Therefore, we should pay attention to the study and training in this aspect in order to be familiar with and adapt to this kind of questions. It is not conducive to the establishment of a flexible knowledge base to list knowledge mechanically by selecting review topics. The review class is short and the knowledge capacity is large. In order to free students from the "sea of questions", the examples in the review class must be carefully selected to get twice the result with half the effort. How to choose, my views are as follows: (1) Examples should reveal the law of solving problems; (2) The examples should be enlightening; (3) The entrance of problem-solving examples should be wide, so that students can seek solutions from different angles; (4) To cover a wide range of knowledge and highlight the key points of teaching materials.