Recently, a video of a 93-year-old professor taking the stage to teach metrical couplets was widely forwarded in Weibo and friends circle. "Three feet platform, only for inheritance. Although I can't arrive, my heart yearns for it! " Netizens have left messages to express their respect for the old gentleman. The old professor in the video is Pan Dingkun, a retired teacher who has taught advanced mathematics all his life at Xi University of Architecture and Technology. 195 1 After graduating from the Mathematics Department of Fudan University, Pan Dingkun became attached to the podium. He stayed on the podium for more than 60 years, and he was still giving a lecture on "I love calculus" to college students until he was 90 years old. In his narrative, the boring mathematical principle becomes vivid: he uses the story of "finding pigs with pigs" to let students understand how to solve unknown mysteries with known conditions, and he will also quote Li Yu's sentence "When is the beauty of youth, spring flowers and autumn moon" to explain the relationship between finite and infinite ... This time, Professor Pan did not talk about his major-advanced mathematics, but chose "Try to talk about the symmetrical beauty in China's couplets and poems." I have been studying in a private school since I was a child, and I am familiar with poetry and meter. He saw some poems in publications and often frowned and said, "It's not even right." In order to give a good lecture, Professor Pan carefully prepared for several months and wrote a thick stack of speeches. Laughing at "teaching people to fish", he found himself a powerful "backing"-a Chinese dictionary. He "translated" the contents of the Chinese Dictionary about the metrical patterns of poetry, copied quatrains, rhymes and oblique patterns with a brush, and drew red circles where the metrical patterns could not be strictly followed. "In fact, mathematics is similar to poetry." In Pan Dingkun's view, mathematics is a poem expressing the laws of nature. Mathematics expresses the laws of nature, while poetry expresses people's will and feelings. "Both are abstract, but both are very profound, accurate and concise, and both emphasize the beauty of symmetry." I have been wearing a navy tunic suit for many years, a magnifying glass with me, and Putonghua with a slight accent of Jiangsu and Zhejiang ... On the afternoon of May 16, Professor Pan, who was on crutches, just entered the classroom that could accommodate more than 100 people, and received warm applause. In the nearly two-hour report, he always stood on the podium, telling his growth process, taking everyone close to the "flat" of Tang poetry and Song poetry, and feeling the profoundness of traditional culture. He didn't use a microphone, didn't take a break, and didn't take a sip of water. Four blackboards were erased and erased, and they were written and written. When he couldn't remember the content of the speech, he picked up a magnifying glass and studied it carefully. No one presided over the opening ceremony, and he finished all the contents in the scheduled time. At the end of the lecture, the teachers and students who came here were surrounded by the old professor. Among them are old professors with the same gray temples, young students who came from another campus by school bus, and old alumni who have graduated for many years. "The teacher's classroom conveys a deep teacher's feelings and love for Chinese excellent culture." A young teacher said. "I don't have heart disease or high blood pressure. Get a pension every month and do nothing. It's a pity to burn a fire. "