Unshudo USM-65 Abacus Solomatic 23 Digit Case with

Bankruptcy is possible with just one touch. Perfect for speeding up calculations. Comes in hard case. [Hippo balls] Birch: Type of tree used as material. Dense and hard wood. Kava balls are brown balls and are the most commonly used. For beginners to advanced users [Features of soroban] ・It is said that learning the abacus improves not only ``calculation ability'' but also ``concentration'' and ``patience.'' ・The material of the ball is carefully selected and carefully adjusted to last for a long time, so you can use it with confidence whether you are a beginner or an advanced user. [Body size] 333 x 65 x 18mm