1. Find the root of the problem: First, you need to find out why you can't understand math. Is it because the basic knowledge is not solid, or because of the fear of mathematics? Or is your learning method wrong?

2. Supplement basic knowledge: If your basic knowledge is not solid, then you may need to learn from scratch. You can find some textbooks or reference books for junior high school mathematics and review them in chapter order.

3. Change your learning method: If your learning method is wrong, you may need to try some new learning methods. For example, you can try to learn math by solving practical problems, or by watching teaching videos.

4. Ask for help: If you still don't know math, you can ask others for help. You can ask your teachers, classmates or parents for help. They may give you some useful advice.

5. Keep a positive attitude: Finally, you need to keep a positive attitude. Learning mathematics takes time and patience. You can't expect to master all the knowledge overnight. As long as you persevere, you can overcome difficulties and learn math well.