Category
page 1Japanese mathematics
abacus
thumb|Bi-quinary coded decimal-like abacus representing
soroban
350px|thumb|A modern soroban. The right side of the soroban represents the number 1234567890, each column indicating one digit, with the lower beads representing "ones" and the upper beads "fives".
counting rods
East Asian numeral system
sangaku
thumb|A sangaku dedicated to Konnoh Hachimangu (Shibuya, Tokyo) in 1859.
Japanese mathematics
Japanese theorem for cyclic polygons
theorem that no matter how one triangulates a cyclic polygon, the sum of inradii of triangles is constant
Japanese theorem for cyclic quadrilaterals
theorem
napkin ring problem
problem in geometry
Equal incircles theorem
on rays from a point to a line, with equal inscribed circles between adjacent rays
Tian yuan shu
Chinese system of algebra developed in Jin dynasty (1248)