Cheng Dawei

Cheng Dawei (程大位, 1533–1606), also known as Da Wei Cheng or Ch'eng Ta-wei, was a Chinese mathematician and writer who was known mainly as the author of Suanfa Tongzong (算法統宗) (General Source of Computational Methods). He has been described as "the most illustrious Chinese arithmetician."

Almost all that is known about his life is contained in a passage written in the Preface of the book by one of his descendants when the book was being reprinted:

The book contains 595 problems divided into 12 chapters. According to Jean Claude Martzloff, historian of Chinese mathematics, "... unlike the authors of the venerable classic, Cheng Dawei was not afraid of superfluity or verbosity. His book is an encyclopaedic hotch-potch of ideas which contains everything from A to Z relating to the Chinese mystique of numbers (magic squares... generation of the eight trigrams, musical tubes), how computation should be taught and studied, the meaning of technical arithmetical terms, computation on the abacus with its tables which must be learnt by heart, the history of Chinese mathematics, mathematical recreations and mathematical curiosities of all types."

The book provided a poem to solve a remainder problem. (Divide it by 3 and multiply the remainder by 70.) (Divide it by 5 and multiply the remainder by 21.) (Divide it by 7 and multiply the remainder by 15.) (Adjust the sum by subtracting or adding multiple of 105, LCM of 3, 5 and 7.)

Cheng Dawei Abacus Museum In the Huangshan City in southern Anhui province in, there is a museum for abacuses named after Cheng Dawei. There are more than 1,000 abacuses and 3,000 copies of related materials displayed in the showcases. These abacuses are made of gold, silver, ivory, jade, stone, hard wood respectively with different shapes.