93-year-old Professor Shu Gao speaks couplets of metrical poems.

Pan Dingkun, a retired teacher of Xi University of Architecture and Technology who has taught advanced mathematics all his life, recently took to the podium to teach metrical couplets. 195 1 Graduated from Mathematics Department of Fudan University, and has been attached to the podium for more than 60 years. Until he was 90 years old, he was still giving a lecture on "I love calculus" to college students. In his narration, the boring mathematical principle became vivid: he used the story of "finding pigs with pigs" to make students understand how to solve unknown mysteries with known conditions, and also quoted Li Yu's famous sentence "When is the spring flowers and the autumn moon" to explain the relationship between finiteness and infinity.

On the afternoon of May 16, Professor Pan, who was on crutches, just entered the classroom that could accommodate more than 100 people and won warm applause. He has been standing on the podium for nearly two hours in the report. He didn't use a microphone, didn't take a break, and didn't take a sip of water. In the scheduled time, he finished all the contents, just like in class at ordinary times.

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.

Pan Dingkun, a retired teacher who teaches advanced mathematics in Xi University of Architecture and Technology, recently took to the podium to teach ancient poetry couplets. He said: "Mathematics and poetry are similar, both abstract, but both are very profound, accurate and concise, and both emphasize the beauty of symmetry."