If the foundation is weak, it is recommended to go through the workbooks issued by the school first. Be sure to master it. Write down all the wrong questions in the wrong book, look through them often, and ask the teacher immediately if you don't understand. Then if you have spare time and energy, you can buy some extracurricular teaching AIDS yourself.

It is suggested that teaching assistants choose a small problem to practice thoroughly (the same type of exercise books make a mountain out of a molehill, make a mountain out of a molehill, etc.). This kind of exercise book is divided into three levels: the most basic, the basic and the other. You can choose the appropriate questions to practice according to your own situation. Moreover, the amount of questions is not large and the difficulty is small, which is suitable for students with weak foundation and also suitable for improving the speed of doing questions after foundation.

If the foundation has been improved, you can make a fuss and do it again. The amount of questions in one pass is large, and the difficulty is gradient, which is suitable for consolidating the foundation and gradually improving.

Finally, don't choose five or three, it will hurt your self-confidence.