As a young man, Cheng Ta-wei traveled extensively throughout populous and wealthy southern China in his visits with renowned mathematicians. At the age of 60 he completed the Compendium of Mathematics, the best-selling book in history on the abacus.
程大位是明朝的數學家，年輕時走遍富庶的江南，拜訪各大數學家，六十歲時完成「算法統宗」這本有史以來最暢銷的算盤書。