The learning of problem-solving strategies is gradually experienced, felt and understood in the process of solving practical problems. Only by experiencing strategies in the process of exploring and solving problems can we understand and recognize the characteristics and values of corresponding strategies and understand their adaptability. In this lesson, first of all, let students pay attention to "where is the complexity" and think about the methods to solve the problem; Then through the way of communication and recognition, choose a method to answer, experience the process of solving problems with "hypothesis", and then think about the similarities between "* * *" in different ideas and what the role of hypothesis is, so that students can feel that the key to solving problems is "hypothesis" and focus on the essential characteristics of methods. Then guide students to review and reflect on the method and process of solving problems, understand the "hypothesis" strategy, and feel that it has been used in previous research and is easy to understand. Students have a good grasp of strategic thinking, but the standard format and test process are not complete when answering questions. The knowledge points and teaching points in the breadth and depth of teaching are in place, but it is inevitable that there is not enough time left in each link, which can further deepen the teaching details and be more conducive to showing students' creativity.