Once, my mother baked a cake, and two cakes could be put in the pot. I thought, isn't this a math problem? It takes two minutes to bake a cake, one minute in front and one minute in the back. At most, two cakes are put in the pot at the same time. How many minutes does it take to bake three cakes at most? I thought about it and came to the conclusion that it takes 3 minutes: first, put the first cake and the second cake into the pot at the same time, 1 minute later, take out the second cake, put the third cake and turn the first cake over; Bake again 1 min, so that the first cake is ready. Take it out. Then put the reverse side of the second cake on it, and turn the third cake upside down at the same time, so it will be all done in 3 minutes. I once saw a report that a professor asked a group of foreign students, "How many times will the minute hand and the hour hand overlap between 12 and 1?" Those students all took off their watches from their wrists and began to set hands; When the professor tells the same question to the students in China, the students will use mathematical formulas to make calculations. 1, triangles are very stable, and many brackets are triangles. Many supports are supported by three feet, and a mathematical axiom is used to determine the plane at three points. 2. Someone nailed diagonal strips on wooden doors to overcome the instability of quadrangles. So is the rolling gate. 3. The stargazing platform in Dengfeng, Henan Province and Sun Yat-sen Mausoleum in Nanjing are both central symmetrical figures. 4. The holes of mosquito nets are hexagonal ~ 5. Chopsticks are tapered. The disc is round. 6. Wires are line segments, refrigerators are cuboids, doors are rectangular, tires are round and the earth is round. Mathematics is a very useful subject. Since the day when human beings appeared on the earth, people have gradually gained a profound understanding of mathematics while understanding and transforming the world. As early as ancient times, there was a legend that primitive people "dabbled in counting" and "knotting a rope". It can be seen that "in some early ancient civilized societies, the beginning and bud of mathematics have been produced" (quoted from the first volume of Ancient and Modern Mathematical Thoughts, p1-author's note). "Before the emergence of mathematics in Babylon and Egypt around 3000 BC, mankind did not make greater progress in mathematics", "After the emergence of ancient Greek scholars from 600 BC to 300 BC", mathematics began to "become an organized, independent and rational discipline" (quoted from the first volume of Ancient and Modern Mathematical Thoughts, P1-author's note) about the history of human development. Nowadays, mathematical knowledge and ideas are widely used in industrial and agricultural production and people's daily life. For example, after shopping, people should keep an account for year-end statistical inquiry; Go to the bank to handle savings business; Check the water and electricity charges of each household. These facilitate the use of knowledge of arithmetic and statistics. In addition, the "push-pull automatic telescopic door" at the entrance of the community and government compound; Smooth connection between straight runway and curved runway in sports field; Calculation of the height of the building whose bottom cannot be closed: determination of the starting point of two-way operation of the tunnel; The design of folding fan and golden section is the property of straight line in plane geometry, and it is about the application of solving Rt triangle knowledge. Because these contents don't involve a lot of high school mathematics knowledge, I won't go into details here. It can be seen that throughout the ages, human society has been developing and progressing in the process of constantly understanding and exploring mathematics. Mathematics has played a decisive role in the development of human civilization. For example, when teaching "Finding the least common multiple of two numbers", at the beginning of the class, I created such a scene: there is a bus from Tanghuang to Changzhou (East) every 6 minutes, and there is a bus from Tanghuang to Danyang (North) every 8 minutes. Now there are only two cars going to Changzhou and Danyang at the same time. How many trains will leave for Changzhou and Danyang in a few minutes? Mathematics is everywhere in our life, from the bargaining of buying vegetables to the design of rockets ... In fact, we study mathematics to cultivate our logical judgment and make our thinking more rigorous. We study mathematics in school not only to remember a formula, but to gradually cultivate our logical thinking ability in the process of learning this formula. It can be said that a person has learned mathematics well. The ability to judge one thing will be greatly enhanced, so learning mathematics well is not just to cope with exams, but to learn a basic skill to survive in society.