He wrote a mathematical treatise called "Hatsubi sanpo" in 1674, and invented a notation system for algebra (which was called Tensan jutsu) to allow computations on paper, and laid the foundations on which more advanced discoveries in the field of Japanese mathematics could later be reached.
延宝2年（1674年）、『発微算法』を著し、筆算による代数の計算法（点竄術、てんざんじゅつ）を発明して、和算が高等数学として発展するための基礎をつくった。