Chapter 9 Section 4 ○ and Digital

In ancient China, there was no pen calculation, and a space was used to represent ○ in the calculation, and the space was a symbol without a stroke.There are many detailed drafts in the Song and Yuan calculation books.The numbers in the detailed sketches are formed by borrowing chip numbers and adding a symbol of ○. In the 1340s, Qin Jiushao and Li Ye, who were divided in the north and south of China, used roughly the same numbers.The number of Li Ye in the north is: Southern Digital will