The main content of western mathematics is to prove theorems, while the main content of China mathematics (focusing on ancient times) is to solve equations, solve various problems, and focus on calculation. It is necessary to talk about the process, method and steps of calculation. The essence of China's ancient mathematics is to proceed from problems, which is completely different from the western axioms. In other words, China ancient mathematics is an algorithmic mathematics, which is also a computer mathematics. In this sense, our oldest mathematics is the most suitable modern mathematics in the computer age.