Xi 'an scored 657 points in the college entrance examination. According to the relevant information, kira is a famous teacher in the postgraduate mathematics institution. The postgraduate mathematics official website shows that kira is 25 years old this year. Xian graduated from the Department of Mathematics of Shanghai Jiaotong University with a master's degree. The teaching ideas are clear, humorous, and the knowledge points are explained in simple terms. The main subjects are high numbers, line generation and probability. He is a teacher in Qi Hang. The cumulative broadcast volume of postgraduate mathematics videos has exceeded 6.5438+0 million, which is deeply loved by the majority of candidates.