Actually. It took almost two weeks in the evening, although it was not continuous, because I didn't get the textbook in advance. The score is about 140. Every time I get a new textbook, I watch it at home for three nights, which adds up to about 20 hours. The learning method is simple. After reading the example, you can deduce it yourself (many people start with the answer to the example, and I think this method is wrong). Don't do the questions after class, just read them page by page. This kind of thing is like building a wheel to learn programming. Mathematics in high school is very simple. You can invent it all the way by yourself and compare it with the textbook. So once you read the answer to the example, you will lose this opportunity forever. But then again, the order of textbooks in Guangdong is chaotic, which is not conducive to self-study. Students in Guangdong have to take my textbook if they want to do this. The older these math textbooks are, the better. Later, when I was analyzing mathematics in high school, I read all the quotations from Chairman Mao, which was super easy to accept. Later, I went to college and got a terrible textbook, although the content was exactly the same.