abakus

ABACUS TECHNIQUES

The following techniques are Japanese and use a modern 1:4 bead Japanese soroban. I love Japanese soroban and it is the style of abacus I most often use. Collecting them has become a passion. Many soroban are beautifully crafted and wonderful to look at; especially the older ones. Some of the soroban in my collection have been signed by the craftsmen who made them and I love the way they work and feel. Some of them have been signed by their original owners. Each has its own history.

However, for some people the soroban may not be the instrument of choice. As already mentioned the Chinese have their own version of the abacus, a 2:5 bead suan pan. There are those who prefer to use a Chinese instrument because it has a larger frame and larger beads allowing for larger fingers. It really doesn't matter which instrument you use. The procedures are virtually the same for both and these methods are well suited to either instrument.

The Japanese Soroban

Fig.1

A soroban is made up of a frame with vertical rods on which beads move up and down. Dividing the upper and lower portion of the soroban is a horizontal bar called abeam or reckoning bar.

Simple addition & subtraction

When using a soroban to solve problems of addition and subtraction, the process can often be quite straightforward and easy to understand. In each of the six examples below beads are either added or subtracted as needed.

Simple Addition

Simple Subtraction