With Yang Chao, only those who can't keep up, those who can't keep up and didn't do well in the exam. I have a good foundation. During the summer vacation, Zhang Yu and Yang, who have been listening to the basic and intensive classes for one year, began to brush the questions. At this time, it was found that the grade of senior three was unstable, and the score was high and low, which showed that the calculation was still a little unstable. At this time, I have a feeling and idea about mathematics, and I can see that the problem lies in basic calculation skills. Yang Chao focuses on three main calculations.