There are several points to note:

1. Be proficient in the last lesson before previewing. Mathematics has many contexts, so we can't just preview or review the knowledge points together.

2. Can't keep up with the teacher's ideas and progress. Maybe you didn't understand what some teachers said. After school, read all the previous knowledge from shallow to deep, and do some basic questions (remember to do basic questions) to deepen your impression, and you will catch up slowly.

3. Have confidence in yourself and stick to it. Even if you can't keep up with the teacher for a while, you should try to understand and never give up. Learning is a slow process, and it needs to accumulate rather than gain weight at once.

Finally, I hope you can keep up with the teacher's rhythm as soon as possible.