1, the classroom structure is reasonable, and students' thinking characteristics are emphasized.

From guessing to verification to adjustment, Mr. Jiang let students know the method of enumerating problems in the form of tables, and realized the changing law of "the head remains the same but the legs" when enumerating and adjusting. Considering the limitation that some students' thinking can't jump directly to the hypothesis method, it lays the foundation for teaching the hypothesis method later. And on the basis of understanding enumeration method, optimize the problem-solving thinking of learning hypothesis method. Ampere classroom conforms to the characteristics of students' thinking development and faces all students.

2. Clever design, accurately find the breakthrough point of classroom difficulties.

Since the rabbit stood up, students have been deeply attracted by this unique way of thinking about problems, and the scenes needed for the problems can be vividly constructed in their minds. After a series of questions, the students realized the ingenuity of the thinking of "changing and unchanging" in mathematics. What is missing? Whose is it? Why? Students can solve this problem soon. The image of the original blunt hypothesis method is presented to the students, and the idea of solving the problem also appears clearly.

3. Understand the meaning of each step clearly and repeatedly.

Students say the meaning of each formula on the blackboard, and the teacher shows the solution process again on the big screen and expounds in detail what each formula requires and why. It seems verbose, but it is actually quite necessary. Some students may not really understand the calculation process, but just imitate the steps of solving problems. Every time, the teacher asks the students to understand the meaning of each formula in detail, which effectively avoids this situation and allows the students to really understand it, so that they can draw inferences in the future.