The biggest difference between high school mathematics and junior high school mathematics is that there is no need to think at all, and everything is clear according to the routine. However, with the increase of problem-solving methods and the integration of knowledge in senior high school, it is necessary to think over and over again during the exam, which means you need to know clearly what you want to do, what conditions you need, and what ideas you need to use to see a topic. For some existing and unique topics, you should know clearly what you want to do, avoid aimless random calculation, waste time and get no points. This needs to be cultivated at ordinary times. Junior high school exams can be handled by memorizing formulas. In high school, you should learn to sort out and summarize. You should know what's behind the formula in the book and what to test in every exercise you do. It may be difficult at first, but it is valuable. You should organize more, so that your knowledge will be a whole piece and you won't feel trivial. For example, after learning conic curves, you will find that elliptic hyperbola parabola is actually in essence. At the end of the study, if you can feel that you can think of a big piece from a problem, it means that your arrangement is effective and your knowledge is interlocking, not scattered, so that you can cope with it when solving problems.
Practice is necessary, but it's just a means to make you chew on the knowledge of books. Don't ask questions about the sea blindly. According to the training intensity of ordinary high schools, you will be exposed to all the college entrance examination questions. There's no need to find your own problems. It is important to digest each question and suggest a group of wrong questions, so that you can often reflect. Whether you can make mistakes before is progress.
Pay attention to calculation. Many people think that the calculation is a minor problem and the final exam can be changed. This is usually cultivated. Don't let go of calculation mistakes every time. Be hard on yourself and be more demanding. Only in this way will you have confidence in the exam and won't worry about calculation.
Finally, I want to say that everyone's state is not static. My high school solid geometry is not suitable. Once there were more than a dozen students in my class. I chatted with my teacher and found some regular methods of solid geometry. Finally, the college entrance examination can easily get rid of solid geometry, so don't be discouraged. Communicate with parents and teachers and discuss problems with students who have learned well. You'll get through this.
Good luck in the college entrance examination. Scientific life is actually wonderful, not just numbers and formulas.