If you are poor at math for exams instead of competitions, my personal suggestion is to put down the problem for the time being. It is very difficult to improve your ability to solve mathematical problems in 20 days, but it is completely enough to consolidate your previous knowledge. You can read the definition of the textbook first to ensure that there are no missing knowledge points, and you can read those knowledge points very well in about two or three days. This time, you must be serious, on this basis. Then practice all the exam questions in your key middle school for several years. As long as you have a little unclear knowledge, you should go back to the textbook, find the corresponding chapter and have a good look. If you really can't, you can choose to give up, which will only give up a small part of the score. After practicing for more than ten days, the effect came out. I heard this from a math teacher who had a great influence on me. It's very effective for me to practice it myself. it wont hurt you to try it