also known as Aida Ammei, was a Japanese mathematician in the Edo period. He made significant contributions to the fields of number theory and geometry, and furthered methods for simplifying continued fractions. Aida created an original symbol for "equal". This was the first appearance of the notation for equal in East Asia. Selected works In a statistical overview derived from writings by and about Aida Yasuaki, OCLC/WorldCat encompasses roughly 50 works in 50+ publications in 1 language and 50+ library holdings. 1784 — OCLC 22057343766 1785 — OCLC 22049703851, Counter-arguments with seiyo sampō 1787 — OCLC 22056510030, Counter-arguments with seiyo sampō, new edition 1788 — OCLC 22056510044 1797 — OCLC 22057185824 1801 — OCLC 22057185770 1811 — See also Sangaku, the custom of presenting mathematical problems, carved in wood tablets, to the public in shinto shrines Soroban, a Japanese abacus Japanese mathematics Notes References Endō Toshisada (1896). . Tōkyō: _. Restivo, Sal P. (1992). Mathematics in Society and History: Sociological Inquiries. Dordrecht: Kluwer Academic Publishers. ; Selin, Helaine. (1997). Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Dordrecht: Kluwer/Springer. ; Shimodaira, Kazuo. (1970). "Aida Yasuaki", Dictionary of Scientific Biography. New York: Charles Scribner's Sons. David Eugene Smith and Yoshio Mikami. (1914). A History of Japanese Mathematics. Chicago: Open Court Publishing. – note alternate online, full-text copy at archive.org External links 18th-century Japanese mathematicians 19th-century Japanese mathematicians Number theorists Geometers 1747 births 1817 deaths Japanese writers of the Edo period