Wu once wrote a couplet for the street gate of his father's house: "People live under the clear sky of a square basin of cypress wood." Red paint and black paint are very nice. On the first day of the first month, Mr. Wu took his son Wu to pay a New Year call to his father. At lunch, grandpa asked his grandchildren, "Have you seen the couplets on the street door? Who can talk, tell me. " Wu's uncle spoke first: "Now the whole country has taken off the five-color flag and put on the blue sky and white flag." I talked about the last sentence of this couplet, and how it fits with reality. Another brother, because he lived with his grandfather, immediately added, "Our family lives in Yong Guang Middle Street, which is adjacent to Chunshu Hutong in the south and Fanghuzhai in the north, so it's better to download the couplet and point out our address." At that time, Mai was a student in the preparatory class of the Mathematics Department of Normal University, and said nothing. Mr. Wu asked him, "Why don't you talk?" Hong Mai said, "All the words have been finished by my brothers. I have nothing to say. " Mr. Wu said, "Can you tell us something about the making of square pots and Chinese toons?" Because I don't know these two allusions, Hong Mai suddenly froze. Mr. Wu wanted to say a few words about him, so he wanted to come and pay a New Year call to his father so as not to spoil the fun for the old man. It happened that the food was already on the table, and the old man changed his mind.

A few days later, Mr. Wu called his son to his side and asked him to solve the "square pot" and "toon". Because Hong Mai had checked the books in advance, he immediately replied, "The word' square pot' means that there are three immortals living on the sea, and one of them is called a square pot. Dong Fangshuo lived on Fanghu Mountain after becoming an immortal. The word' Toona sinensis' means' Toona sinensis'. As "Zhuangzi" said, those who had Toona sinensis in ancient times took 8,000 years as spring and 8,000 years as autumn. Dad linked' Square Pot' and' Toona sinensis', which means wishing grandpa a long life. " Hong Mai was very proud when he finished, thinking that his father would praise his son's sentence. I didn't expect Mr. Wu to say, "If you are forced to ask, you will turn over the books and perfunctory things. If you don't say anything, you won't know how to study consciously. You have become a college student, and you have no intention of' studying wholeheartedly'. How can this go on? " From then on, Hong Mai remembered his father's lesson and studied hard. He is not only excellent in mathematics, but also has rich knowledge of literature and history. He is also good at Kunqu opera, calligraphy and poetry. After graduating from Normal University, he stayed on as a teacher and became one of the outstanding professors in the Department of Mathematics for decades.