About the Japanese abacus

The first abacus was used somewhere around 2700 – 2300 BC and, having gone through various stages of development still survives in Russia in the form that we’re all familiar with. It has 10 rows of 10 beads each, the top row counting from 1 to 10 and the next row from 10 to 100 and so on. It can hold numbers up to 11 111 111 110. This is the abacus that many schools (including ours) use to teach numeracy. The first two pictures are taken from Google.

Somewhat later, the Chinese tipped it on it’s side and eliminated three of the beads in each column. The beads count as numbers when they are against the middle bar. The bottom 5 on the right hand column count from 1 to 5 and the upper two are the 5 and 10 beads. The next column from the right is the 10s column, then the 100s and so on, so this one also counts to 11 111 111 110, but uses 70 beads instead of 100. It is still used in China to this day.

Later still, the Japanese realised that there were still more beads than necessary and they developed the Soroban, which is the one we teach at the school. Here is a graphic before any number is entered.

To enter the number 1, move the bead as shown using the pad of the right thumb, unless you are left handed (correct fingering is critical for speed).

To enter 2 move the next bead up. All of the lower beads are always moved with the thumb.

And the number 3 by adding one more bead

You can guess how to do the number 4

Now for number 5. The upper bead is the 5 bead, so simultaneously slide it down using the pad of the forefinger, while sliding the 4 beads down to clear them.

Now let’s form an 8. We’ve already got a 5 so we need another 3, get it?

18 needs the ten bead.

And 78 needs a fifty and another 10. You pinch them to the bar simultaneously, using thumb and forefinger.

Want to try 378?

And 6378? Another pinch.

So there you are. Now, do you think you could picture the abacus in your head and move those beads on the imaginary abacus, then read the answer from the final result? That’s called Anzan (pronounced unzun). If you can do it, you’ll be using your right brain (pictures, creativity etc.) co-operatively with your left brain (logic, calculations etc.). Just think about it. How many other activities can you think of with the same co-operative balance? I can think of chess (right brain pattern recognition, left brain strategy and tactics).

It is because of Anzan that we feel that abacus maths is so important for our kids that we make it compulsory. We also encourage them to play chess for the same reason. In later articles, I’ll show you how to add, subtract, multiply and divide.


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