Yes Teacher Gu Sen has a junior high school math class, and Gu Sen is a math popular science writer who is engaged in math education in primary and secondary schools. He helps students cope with the college entrance examination or competition through ordinary math training. Gu Sen graduated from the Chinese Department of Peking University, and is a popular science writer in mathematics. He has written Joy in Thinking: Matrix67 Notes on Mathematics, Amazing in the Bathtub: 256 Interesting Questions that Make You Suddenly Realize, etc.