3 ms·
Soroban. Japanese abacus. Every number only has one representation. +-*/ and other calculations. http://totton.idirect.com/ http://totton.idirect.com/
by jbaber 2y ago
Soroban. Japanese abacus. Every number only has one representation. +-*/ and other calculations.
http://totton.idirect.com/ http://totton.idirect.com/