1. No reasonable plan was made. Children lack goals in their studies and don't know what to do every day. It seems that I study late every day, but actually I only finish my homework and spend the rest of my time "hanging out".

I didn't understand some things before. A lot of knowledge is coherent, not isolated and scattered points. If you don't understand the previous knowledge, it may lead to the failure to connect the later knowledge.

3, suddenly addicted to novels or games. This not only affects sleep, reduces the quality of class, but also makes you think about the plot of the novel in class and lose concentration in class.

4. The foundation is not solid. Usually, the exam questions are simple, the organization is lax, the invigilation is lax, and the marking is random, which makes it easier for many students to "fish in troubled waters", such as plagiarism, and change the answers while the teacher is not paying attention. In particular, some students usually study frivolous and muddle along, so they can't be strict with themselves in their studies. This will lead to a serious shortage of mathematics learning foundation.