He formulated a relatively complete theory of weights and measures; He proposed to adopt the calendar of Zhuan Xu Calendar; He also added and deleted nine chapters on arithmetic, some of which were earlier than those in Europe 1500 years ago.
He made great contributions to the development of mathematics in the world, and Zhang Cang was also an ancient scientist who advocated the abolition of corporal punishment in the history of China.
Later, the palace was promoted to a doctor by the emperor, but Zhang Cang was gradually left out in the cold, so he retired. After returning to his hometown, Zhang Cang began to do nothing to study health preservation. There is a historical record that says,
After Zhang Cang left office as prime minister and returned home, he was old and had no teeth in his mouth, so he specially raised more than 100 women and provided him with human milk, saying that this would prolong his life.
Another thing is that he is no longer close to anyone who is pregnant and has children. He finally lived to be over one hundred years old before he died.