Look at the topic, everyone has talked about it. Some students said, "Rent three big boats first, rent 30 yuan, and 28 people need to rent seven small boats, rent 56 yuan and rent 86 yuan." Some students also said, "Rent five big boats first, rent 50 yuan, 16 people need to rent four small boats, rent 32 yuan and rent 82 yuan." After listening to this, everyone thinks that the second rent method saves some money than the first rent method, but some students don't think this rent method is the most economical method, especially Tao Jinsong, a little mathematician in our class. He stood up and said, "I have another way to save money more than this." We can rent seven big boats to rent 70 yuan first, and four people only need to rent 1 boat and then rent 8 yuan, one * * *.
Just as we were arguing, the teacher motioned for us to calm down. He said: "Tao Jinsong is really clever and found a way to save money." After listening to the teacher's praise, we are also happy for Tao Jinsong. Then the teacher said, "How can we find the most economical method quickly and well?" After listening to the teacher, we had a heated discussion again. At this moment, I raised my right hand. When the teacher saw me raise my hand, he told me to stand up and answer. I said, "First of all, we should carefully examine the topic, then think in a certain order according to the requirements of the topic, and rent a big ship first, but we should pay attention to the fact that the number of people left is exactly four times, so as to ensure that every big (small) ship is full." We can also use the list method to solve this problem. The list is not only convenient for thinking, but also ensures that there is no repetition or omission in the answer. "After listening to my narrative, the teacher kept nodding. At this time, the classroom burst into warm applause again, which seemed louder than the applause just now. I was unhappy.