The distribution of key and difficult problems in senior high school entrance examination mathematics is 7: 2: 1. According to the results of the survey on the mathematical planning of the senior high school entrance examination in Beijing, 70% of the questions are not easy to score, because each question is relatively simple, and some numerical values or knowledge points affect the judgment, which leads many people to lose points if they can't see it. 20% of the questions are difficult for many people, and it is difficult to find a solution without thinking for ten minutes. It has a wide range of knowledge points, and most people can't understand the questions, so it is almost impossible to get this part of the score. The remaining 10% questions are extremely difficult, and few can be worked out in the province. Almost 100 people do some steps every year, and only100 people do something wrong. It can be seen that it is difficult to get 90 points in the senior high school entrance examination. Generally, people who pass the exam are equivalent to more than 120 people who usually take the math exam.