Book Japanese Abacus Theory
By Takasho Kojima “The Japanese Abacus / It’s use and theory” (English). Written originally 1954 and (3rd version) printed 1961, imported from the United States.
Personal collection of vintage and modern Abacuses / Abaci.
By Takasho Kojima “The Japanese Abacus / It’s use and theory” (English). Written originally 1954 and (3rd version) printed 1961, imported from the United States.