Are you in grade three now? It's a little late to start learning now. But there is still great hope. After all, man can conquer nature! Recommend a book about Olympic Mathematics: Excellent Lecture Test of Olympic Mathematics, which is very good. It is suggested to buy a complete set by grade, that is, one set for 20 yuan in grades 6 to 9. It's good and cheap, but if you spend about half an hour every day, you can't do anything. It is best to spend two hours a day, at least 1 hour. That's all I want to say. How to do it is up to you! I hope you can stick to it and get into your ideal high school!