On this day, 31 years ago, on March 24, 1994 (February 13, 1994 in the lunar calendar), experts from the Zhangjiashan Han Tomb in Jiangling, Hubei Province verified that the owner of the tomb was Zhang Cang, a mathematician of the Western Han Dynasty. On March 24, 1994, experts found that the owner of the Han tomb in Zhangjiashan, Jiangling, Hubei Province was Zhang Cang, a mathematician of the Western Han Dynasty