Time unit is not as easy to express as length and mass unit, and it is abstract and difficult for students to accept. This lesson is entitled "How long is the score of 1". Experience the length of 1 through various practical activities, so that students can appreciate the length and value of time, knowing that 1 is 60 seconds. Let me ask a question first: children, do you think 1 minute is long or short? Some talk long, some talk short, and the children argue endlessly. Then, I asked my children to look at the clock face number 1, 2, 3 ... and experience the speed of the second hand, and observed that 1 minute =60 seconds. Then, I prepared several activities to let the children feel the length of 1 minute. 1, sit still 1 min. 2. Pump 1 min. 3. Reading 1 min. 4, oral calculation 1 minute. 5. Write 1 min. Through activities, children find different things and feel that the length of 1 minute is different. Generally speaking, 1 minute is very short, so cherish the time. Because they experienced a lot in class and arranged some experience activities after class, the children experienced the length of 1 minute very deeply.