Using a Soroban - Japanese Abacus

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The soroban, a Japanese abacus, is a centuries-old tool used as the original calculator by bankers, merchants and school children. It is derived from the Chinese suanpan (abacus) and was introduced to Japan from China in the 15th century.

Even though nearly everyone in today’s world uses calculators, the soroban is still used in Japan and is valued as an effective tool for school children to help them understand how numbers work. As a manipulative counting tool, the soroban helps to bring numbers to life by physically touching, as well as a seeing, the beads that represent numbers. It is an excellent way to visually show the decimal number system.


The Soroban Concept

A soroban usually consists of a wooden frame with vertical rods (columns) that beads slide on and a horizontal divider bar, called a “beam” or “reckoning bar,” that separates beads into two groups. The upper row of beads is referred to as “heavenly beads”, and the lower beads are called the “earthly beads.”  Sorobans always have an uneven number of columns, but never less than nine. Basic sorobans usually have 13. Larger versions can even go up to 31 to allow for calculation involving more digits (each rod represents a digit).

The heavenly (upper) beads are each worth “5”, while the earthly (lower) beads are worth “1.” When a bead or group of beads touches the beam it represents these values. On a particular rod, for instance, if one heavenly bead is moved down to touch the divider beam, and two earthly beads are moved up to touch the beam, the value represented for that column is 7 (5+2). And so it goes, column by column, to create larger numbers.

Dots on the beam that mark every third rod are called “unit points” and designate the last digit of a whole number. Any number that is represented on rods to the right of a unit point is part of the decimal portion of a number. Unit rods to the left of a designated unit rod aid in placing value by denoting number groups – ones, tens, hundreds, thousands, millions, etc.


Interactive math to master complex processes

By moving the beads up and down and seeing the numbers being represented, instead of merely memorizing math answers, students become active participants in the math process. While their peers are simply memorizing math facts, Japanese students using a soroban are constantly manipulating numbers by breaking them down into their component pieces, which makes it easier for them to understand and learn complex math processes.

Experts say that after two or three years, students don’t need a physical soroban – they can do the math in their head.

The Japanese Chamber of Commerce and Industry conducts examinations, which soroban users can take to obtain licenses. There are six levels of mastery, staring from sixth-grade (very skilled) all the way to first-grade (for those who have completely mastered the use of the soroban). Those who obtain at least a third-grade license are qualified to work in public corporations.

Use of a soroban also has value in other areas of life. Working with numbers on the soroban leads to numerical fluency that helps students understand advanced math concepts and even helps with other disciplines such as science, engineering and accounting, because of the concentration and logical thought processes developed through soroban use.


Build your own soroban

Now that you’ve read an overview of the soroban and its effectiveness as a learning process for math, you may want to consider building your own soroban or purchasing one for your children or grandchildren. It would be an excellent project for woodworkers to fine-tune their hand tool skills as they cut, join, drill and finish their own version of this math aid.

Although sorobans are made of a variety of materials, most Japanese soroban frames are built of wood and have either wood, metal, rattan or bamboo rods and wood beads. Beads can also be made from marble, stone, or even plastic.

Even though we now use calculators, there is still a place for the soroban. It’s a great visual aid for learning math, and it helps develop concentration. It adds up to being a cool school tool with a lot of tradition – a “new twist” to learning that can generate interest in math.

Check out the short video below of Product Manager George Snyder actually building the soroban that was used on the cover of our May 2017 Japan Woodworker catalog.

If you decide to build a soroban, visit JapanWoodworker.com for the tools and supplies you need – and be sure to take a photo and send it to us along with your comments to Blog@JapanWoodworker.com.



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