When checking homework, it is found that many math teachers only care about the correctness of exercises when correcting math homework, and rarely care about the use of typos and punctuation marks. Some math teachers think that typos and punctuation are the business of Chinese teachers, not math teachers. Under the red tick in students' exercise books, we will also find some inappropriate new terms, such as flat "square" and folded "square" statistical charts, as well as countless incomplete answers and many jokes. In fact, this is not only related to the math teacher, but also has a great relationship. Seeing this, I thought of a math teacher in junior high school. He is a very serious person. Every time we do math homework, he will carefully correct it, not only correcting the data of the exercises, but also carefully checking whether each step and link is correct and reasonable. What is even more incredible is that every time he corrects his homework, he circles the wrong words in it. Once, a classmate didn't draw the last period in the "answer" of the last question, and he did it seriously. Therefore, among our classmates, regardless of the homework of other subjects, math homework is very serious. Whether the exercises are correct or not, the format and writing are the first. Now that I think about it, it is his earnest correction of "not even letting go of the last full stop" that has formed the habit of taking our homework seriously.