About the features of The Kamedake Soroban
The Kamedake Soroban has its unique features which distinguishes itself from the others.
Concave on the Frames
The upper and lower frames have smooth concave surfaces, so that you can hold the Soroban easily and naturally.
On the upper and lower frame there are white spots. These are Entry (Nyurank) spots. For multiplication on the abacus, the most common mistake is said to be about the decimal point (the zero). The Nyurank spots are intended to help prevent these mistakes.
- ・One-digit multiplication uses the upper-frame spot.
- ・Two-digit multiplication uses the main center-bar spots.
- ・Three-digit multiplication uses the lower-frame spot.
In that way decimal-point errors are avoided.
※ The Nyurank system is included in the most of the Risou-gata, Magnetto and Sorotop series sorobans.
※ In the Risou-gata soroban series, numbers 3435 and 1440 do not have the Nyurank points.
Jyuubako-gumi or Mortise & Tenon Joint