Let's play a game-driving a train. Select a few students to follow the teacher, form a "train" and "run" slowly around the corridor in the classroom. 1. The rest of the students observe the number of people who make up the "train", find out the position of the teacher and each student in the queue, and communicate with their deskmates. The "train" changed its direction, and the "locomotive" became the "train tail". Observe and tell the position of the teacher and each student in the queue at this time. 3. Guide students to understand that when counting, the direction of counting is different, and the result is different.