Book Abacus Arithmetic
Abacus Arithmetic – How to Perform Some Calulations on the Chinese Abacus / Author Welton J. Crook / 70 pages / Printed 1958 / Published by Pacific Books (Palo Alto, California, US)
Personal collection of vintage and modern Abacuses / Abaci.
Abacus Arithmetic – How to Perform Some Calulations on the Chinese Abacus / Author Welton J. Crook / 70 pages / Printed 1958 / Published by Pacific Books (Palo Alto, California, US)