Japanese Abacus (Soroban): User Guide
of reading - words
Want to know how to use a Japanese abacus?
No problem! We are passionate about this topic and through a series of tutorial articles, we will help you understand how to use a soroban.
Without further delay, let's get started!
Using the Japanese Abacus Today
In Japan, the abacus is called a "soroban." Japanese students begin learning how to use the abacus as early as the third grade.
Even today, in modern times, some cashiers in Japan still use the abacus. And when they calculate with it, they are almost as fast as when using a calculator, sometimes even faster.
How the Soroban Works
The figure above shows a Japanese abacus.
- A Japanese abacus is composed of counting beads. The beads on the upper deck are called five-unit counters, while the beads on the lower deck are called one-unit counters.
- The vertical rods holding the counters determine the place value of the numbers represented by the counters. From right to left, there is the ones place, tens place, hundreds place, and so on. Some Japanese abacuses include decimal places.
- You can represent a number on an abacus by moving the one-unit counters upward on the lower deck and/or by moving the five-unit counters downward on the upper deck. Moving a one-unit counter upward adds 1, 10, 100, etc., depending on its place value. Moving a five-unit counter downward adds 5, 50, 500, etc., to the number's value.
How to Represent Numbers on the Japanese Abacus
In this section, we will learn how to represent numbers using the Japanese soroban. The starting position of the Japanese abacus is shown above, where all five-unit counters are pushed to the top, and all one-unit counters are pushed to the bottom.
Representing Numbers 1 through 4
The abacus represents 2 because two one-unit counters have been moved upward on the lower deck.
Representing the Number 5 and Beyond
This abacus represents 6 because one one-unit counter has been moved upward and one five-unit counter has been moved downward on the upper deck.
Representing Tens
The abacus in this example represents 12. One one-unit counter in the tens place has been moved upward, so its value is 10. Then, two one-unit counters have been moved upward, so their value is 2.
Representing Hundreds
The ones units represent 6, the tens units represent 70, and the hundreds represent 500, so the value represented by the abacus is 576.
Soroban Number Examples
The images below represent 1,264 and 30,651. Can you see why?
That's all for today. In the next article, we will see how to perform addition and subtraction operations.
Finally, if our explanations weren't clear enough, we invite you to watch this excellent video by Apprends-Moi Autrement
To Go Further with Your Japanese Abacus
How to Add and Subtract on a Japanese Abacus (Soroban)
The Soroban Method: Our Review of the Complete Training
You'll get better with practice, so we recommend getting one if you don't have a soroban yet.
