Cheng Dawei, a renowned mathematician and master of abacus calculations during the Ming Dynasty, was also known by the courtesy name Ru Si. He was a native of Tunxi District. Starting his career in business at a young age, Cheng abandoned commerce later in life and devoted himself to writing. Recognizing the inconvenience of the traditional abacus counting method in commercial transactions, he completed "Suanfa Tongzong" in 1592, consisting of 17 volumes, and a concise edition called "Suanfa Zuan Yao" in 1598, which comprised 4 volumes. These works elaborated on the traditional rules of abacus calculations, established the usage of the abacus, and refined the mnemonic techniques of abacus calculations.