Edo-Period Teens Tackling Math’s Toughest Problems: A Historical Look at Japan’s “Wasan” Math

The sangaku at Myōjōrinji. (Courtesy of Fukagawa Hidetoshi)

Detail of the Myōjōrinji sangaku, showing the problem solved by Kawai Sawa et al. (Courtesy of Fukagawa Hidetoshi)

The mathematical problem solved by Kawai Sawa.

The sangaku at Sōzume Hachimangū shrine. (Courtesy of Fukagawa Hidetoshi)

Colophon in the third volume of Sanpō shōjo. (Courtesy National Diet Library Digital Archives)

The novel Sanpō shōjo (at left; courtesy Chikuma Gakugei Bunko), inspired by the Edo-period wasan text of the same name, and its manga adaptation (courtesy Leed Publishing).

Dr. Antonia Karaisl. (© Abe Haruki)