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  • Juju Kurihara

The power of Soroban -Japanese abacus -

Updated: May 9, 2023

My mum is good at calculation and she is proud of it. When I´m with her, I feel like I have a calculator with me. I just need to tell her the number and she will give me the answer in the moment. I realised one day she was moving the fingers, not like playing piano but like scratching the air. I asked her why she did it and she told me that she was flipping a soroban (そろばん). When we returned home, she showed me many wooden beads lined inside a frame. That was my first encounter with a Japanese abacus and I had no idea how powerful this simple low-tech calculator was.

Abacus is used in many countries and comes in slightly different form. The first abacus in the history was used in Mesopotamia that was a stone tablet filled with sand. They drew lines on the sand and placed stones to calculate. It came to China about 1,700 years ago, Chinese abacus has two balls on the top part whereas Japanese soroban has only one. In the end of the 16th century, soroban was introduced in Japan. The oldest abacus exists in Japan is the one a follower of the shogun Hideyoshi Toyotomi (豊臣秀吉, 1536-1598) used in Kyushu.

When I hear someone calculates with soroban, it gives me an image of a shopkeeper in Edo period (江戸時代, 1603-1867). I know I´m exaggerated but when I grew up, I didn´t see anyone using it in a shop. In my mum´s childhood, there were many places where taught children soroban. But in my childhood, many children were learning piano, ballet, swimming or baseball.

Don´t get me wrong, there are still those small schools outside of school where children or anyone can learn soroban. These schools are called soroban juku (そろばん塾), yes, juku as in cram schools. Just this is not for getting into famous secondary schools or high schools. However, learning abacus could be much better and effective way to train the brain.

The League of Japan Abacus Associations, define six abilities cultivated by learning soroban.

1. Concentration : soroban exam is only ten minutes and you could be calculating multiplications of a six-digit number by a five-digit number. In such condition, any mistakes blow your exam.

2. Inspiration : A doctor of Nippon Medical School has demonstrated that high ranked soroban users use their right brain while they calculate in mind by using soroban method. It´s said that the right brain manages inspiration such as problem solving and invention.

3. Memorization : “In the soroban method of mental calculation, th right brain memorizes the patterns of answers processed. In this method, answers are stored in the long-term memory as intuitive images."

4. Insight : The process of calculation is so fast, you have to have the ability to observe attentively otherwise you make mistakes easily. Through soroban practice, your insight is hugely improved.

5. Information processing : When you do anzan (暗算/ mental calculation), you have to process numbers rapidly and accurately without any mistakes.

6. Speed reading and listening : In soroban practice, yomiagezan (読み上げ算) is introduced, which the problems are read out aloud while the students are expected to understand promptly and mentally process them. This is a good training of speed listening.

You can read full explanation from their website in English :

Soroban is not an ancient calculator, which I thought it was but rather, it´s a piece of paper you take a note while you are calculating many numbers in your head. And the speed they process is not a human velocity. Accuracy? No need to say. I think it´s shame I didn´t learn it from my mum when I was small.

You can see how children train their soroban method. After watching this, I´m convinced the power of soroban really does work.

Those who have never used abacus, here is the basic theory of soroban and how to do addition.

You don´t still believe calculating with soroban can get that velocity? Here is the competition between the master of calculator and the soroban champion. It´s amazing.

References :


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