Discover math problems from daily life: Teacher: (accompanied by health songs) Life lies in exercise. We exercise every day, and moderate exercise can make us healthier. What will happen to the body after exercise? Who can say something? Health 1: You will sweat! Health 2: Breathing will speed up! Health 3: The heart rate has also accelerated! Health 4: The number of pulse beats has also increased! ..... Teacher: Just now, many students talked about the changes that will happen to the body after exercise. We can know the changes of pulse beating times before and after exercise through experiments. (The teacher puts forward the topic: Exercise and physical changes) Activity discussion: Preparation: 1. The teacher will tell the students how many times to take the pulse; 2. Students are free to combine in groups of four and choose a group leader; 3. Requirements for arranging activities: (1) Understand the changes of pulse rate before and after running in situ for 30 seconds and 60 seconds; ⑵ Understand the changes of pulse rate before and after stepping and jumping at the same time. 4. Make an activity plan collectively. Activities: each group carries out activities independently according to the established plan; During the activity, the team leader recorded the data and analyzed it. Discovery: Students make data into statistics or charts. Teacher: What did you find after the activity? Health 1: The pulse really beats much faster after exercise. Health 2: the movement is slight, and the pulse beat changes little. Health 3: After strenuous exercise, the number of pulse beats increases a lot. Health 4: The same exercise, different time, the change of pulse rate is also different. Teacher: Through two groups of experiments, we found that the length of exercise and the different exercise methods will cause the change of pulse beating times. Activity reflection: 1. Ask the PE teacher, how many times per minute is the most appropriate pulse for the third grade students. 4. Consult the knowledge of sports science and make a reasonable "personal exercise plan". Case analysis: The basic starting point of mathematics curriculum in primary school is to promote students' all-round, sustained and harmonious development. We should not only consider the characteristics of mathematics itself, but also follow the psychological laws of students learning mathematics, emphasizing the process of abstracting practical problems into mathematical models and explaining and applying them from existing life experiences. In this case, teachers ask questions from the daily sports activities that students are familiar with, so that students can experience the process of activities and understand the process of abstracting practical problems into mathematical models. Then through the analysis and processing of data to solve the problems in life. It not only creatively uses teaching materials, but also does not deviate from them. Doing so is conducive to stimulating students' interest in actively participating in activities and making teaching activities fruitful. Disadvantages: in this case, the activity plan is designed in the preparation of the experiment, and the students are not allowed to go through the whole research process. Perhaps teachers have paid and gained in teaching, and this is the key to this activity. The value of practical activities lies not in the results, but in the process of making students apply what they have learned and independently study and solve problems. Activities should give students enough space for independent inquiry. Teachers should not rush to give guidance from the question to the final research reflection, which will make students lose the opportunity of independent inquiry and reduce their interest in independent inquiry. Teachers can give timely guidance according to the situation of different groups to ensure the smooth progress of inquiry.