The Japanese Abacus The japanese Abacus, Kojima, Takash. Its use and theory. © Arithmeum Hrsg. Charles E. Tuttle. Company, Inc. of Rutland, Vermont & Tokyo, Japan 1954. Edited by Charles Tuttle. ISBN 0 – 8048 – 0278 – 5. (First edition 1954, thirty-seventh printing 1998)