Japanese Abacus (Soroban)

Soroban, the Japanese abacus, provides a visual and tangible tool that allows students to see and manipulate a physical representation of abstract numbers. The soroban can not only help consolidate arithmetic skills and improve concentration, but also allow the exploration of mathematical concepts through the lens of Japan.

In this article, I’ll take a different perspective on the Soroban, its structure, components, and fascinating uses. Whether you’re looking for a practical tool to learn and enhance mental abilities or want to introduce your child to creative calculation methods, this article is for you. u

Outlines

Soroban Abacus

What is the Japanese Abacus Soroban

History

Origin of the Japanese Abacus
Soroban in Japan
Development of Soroban from Suanpan

Parts of the Soroban Abacus

How Soroban Works

Place Value Concept in Soroban

Representing Single-Digit Numbers
Representing Multi-digit Numbers
Zero Representation in Soroban

Basic Calculations on Soroban

Addition and Subtraction Using Soroban

Mental Calculation Using Soroban

Benefits of Learning Soroban

Japanese Abacus for Children

Learn Soroban Step by Step

Modern Use of Soroban:

Soroban in Japanese Schools:

Conclution

FAQs

Soroban Abacus

What is the Japanese Abacus Soroban

The soroban, known as the Japanese abacus, is a rectangular wooden instrument used for calculations based on the decimal system. The frame is 33 by 6 centimeters. It has vertical rods with sliding beads and a fixed bar across the rods. The standard Japanese soroban used today has 23 rods with 5 beads each, 1 above the bar and 4 below. It is considered the first calculator in Japan and has played a significant role in the country's cultural and educational development. We believe the soroban to be representative of many aspects of Japanese culture.

History

Origin of the Japanese Abacus

The Japanese abacus is called the Soroban. Its origin can be traced back to China, where the Chinese abacus (Suanpan) was invented more than 2,000 years ago. Through trade, cultural exchange, and scholarly contact, the Suanpan was introduced to Japan around the 14th to 16th century. At first, the Chinese abacus was used mainly by merchants and officials for calculations related to trade and taxation.

Over time, Japanese scholars and mathematicians adapted the abacus to better suit their calculation methods, leading to the creation of a unique and simplified version known as the Soroban.

Soroban in Japan

The Soroban became widely used in Japan during the Edo period (1603–1868). During this time, mathematics education developed rapidly, and the Soroban was recognized as an essential calculating tool. It was used in schools, businesses, and government offices.

By the 17th century, Japanese mathematicians refined the structure of the abacus to make calculations faster and more efficient. The Soroban gained such importance that it was formally included in the Japanese education system. Even after the invention of calculators, Soroban training continued because it helps develop mental arithmetic, concentration, and accuracy.

Today, the Soroban is still taught in Japanese schools and is used in international abacus competitions.

Development of Soroban from Suanpan

The Suanpan typically has two upper beads and five lower beads on each rod, allowing multiple ways to represent numbers. Japanese mathematicians found this structure more complex than necessary for their base-10 number system.

To improve efficiency, they gradually simplified the design:

First, the Suanpan was modified to 1 upper bead and 5 lower beads.
Later, it was refined further to 1 upper bead and 4 lower beads, which is the standard Soroban used today.
This simplified structure made calculations quicker and reduced confusion for learners. The Soroban’s design perfectly matches the decimal system, making it more logical and user-friendly than the Suanpan.

Parts of the Soroban Abacus

The soroban is the Japanese abacus, which evolved from the Chinese abacus (the suanpan) by removing one heaven bead and one earth bead to only keep the bare minimum to interact with numbers.

What distinguishes it from the suanpan is not only its number of beads but also the shape of the beads. They are biconal (made of 2 cones), with a thin slice that makes it easier to manipulate the bead and move it up and down.

The parts of the soroban, or Japanese abacus, are

The frame

The frame is the black outline that holds together the soroban parts. The frame is divided into two parts by a horizontal beam called a divider. The two parts of the abacus are known asthe “upper part” and “lower part”. The bar dividing these two parts is called the ‘crossbar’.

The beam

The beam (also called the reckoning bar) is the bar that splits the soroban in 2 horizontally.

The rods

The rods or columns are the stem that holds the beads. Their number defines the size of the soroban. Most of the time, it is 21, but that can vary from 13 to 31 or even more. The bigger the soroban is, the more numbers or the bigger the numbers you can put on it.

The beads

The beads are the basic part of the soroban that are able to be moved on the rods. You can move them up or down, given their current position.

How Soroban Works

The Soroban works on the base-10 number system and uses beads to represent numbers and perform calculations. Each vertical rod represents a place value, such as ones, tens, or hundreds. A horizontal bar divides the Soroban into two parts: the upper bead has a value of 5, and each lower bead has a value of 1. Only the beads that touch the horizontal bar are counted. Numbers are formed by moving beads toward the bar, and calculations like addition and subtraction are done by moving beads toward or away from the bar according to their values. The final position of the beads shows the result, making the Soroban a fast and accurate tool for arithmetic calculations.

Place Value Concept in Soroban

The soroban is a counting instrument with beads on rods in a frame. The frame is divided into two parts by a horizontal beam calleda divider. The two parts of the abacus are known as the “upper part” and the “lower part”. One bead in the upper part is valued five, and eachbeads in the lower part is valued one. Each rod represents a digit, such as ‘Ones’, ‘Tens’, ‘Hundreds’, ‘Thousands’, etc.

The number of rods in a Soroban is always odd and never fewer than nine. Basic models usually have thirteen rods, but the number of rods on practical or standard models often increases to 21, 23, 2,7 or even 31, for calculation of more digits or representations of several different numbers at the same time.

A soroban contains some dot marking in every third rod to designate the last digit of the whole number, which is called the unit rod. The right part of the unit rod is used to calculate a decimal number. The unit rod is always designated as 1’s, immidiate left rod is designated as 10’s, the next immediate left rod is designated as 100’s, then thousands, millions, etc.

Representing Single-Digit Numbers

Let’s start representing numbers on the soroban.

To display numbers, you will have to choose one rod with a unit point and move one bead upwards. This represents 1. You can represent 2 by sliding one more bead upwards. Now you can see that there are two one-beads in the upward position on the crossbar. Moving one more bead upward adds to the existing ones, making it 3 or 4, depending on the number of one-bead moves you make.

For representing 5, we use the five-bead instead of one bead. To represent the numeral 5, you just need to slide the five-bead downwards and move all the one beads down. This equals 5.

Keeping the five beads down, you push one one-bead up to represent 6. You can see that one five-bead and one one-bead pushed towards the crossbar represents 6 (5+1=6). You can set 7, 8, and 9 by moving an additional bead towards the crossbar.

The numbers of the soroban (0-9) are composed of one bead and a five-bead. This 1-5 number system plays an important role not only in soroban calculation but also in Japanese culture.

Representing Multi-digit Numbers

You can see that setting 9 uses up all the beads on the rod/columnthat it has, and we will not be able to add any more beads to it, so we need to use the next rod/column on the left. This second rod represents tens, and hence it is called the ‘tens column’. To set 10, reset the ‘ones column’ to zero position and move one one-bead up to the crossbar. Now we have 10. The soroban system uses something similar to the Arabic system while writing multi-digit numbers. For example, for writing 10, we join 1 and 0 together so that the total value becomes ten. Similarly, the case in soroban, where each rod/column has a specific value. To represent 11, we keep the 1 bead in the ‘ten column’ and move the one bead up to the crossbar.

You can see the double ‘1s’ next to each other as we write in the Arabic system. It is now easy for you to represent 12, 13, and 14, and so on up to 19. To make 20, we need to slide down the ones bead to zero and shift up two ones beads on the tens column. Hence, 20 consists of 2 in its tens digit column and zero in the ones digit column. It is easy to set 20 after resetting the soroban to zero, as in this case, you just need to lift up the two beads in the tens digit column.

Zero Representation in Soroban

Zero on the Soroban is represented when no beads are touching the horizontal bar on a rod. This means both the upper bead and allthe lower beads are kept away from the bar. Such a rod shows a value of zero for that particular place value. This clear visual representation helps learners understand the concept of zero and place value, making the Soroban an effective tool for building strong number sense.

Basic Calculations on Soroban

Addition and Subtraction Using Soroban

1. Line up your first number

Let’s add 2,145 and 5,668. First, reset your abacus to its default position. Then enter 2,145 on the abacus by pushing down a top row bead in the “ones” column, pushing up four bottom row beads in the “tens”, one in the “hundreds”, and two in the “thousands”.

2. Start adding from the largest place value

The first numbers you'll add are the 5 to the 2 from the “thousands” column. Push a single bead from the top row of that column down and keep the two beads from the bottom row up. The “thousands” column is now a 7-digit column. Likewise, add 6 to the 1 in the hundreds place. Move the top row bead in the “hundreds” column down and push another bottom row bead up to make a 7-digit number.

3. Carrying over

Adding 6 to the 4 in the “tens” column will result in 10. You'll carry over a 1 to the “hundreds”, making the 7 an 8 in that column. Next, push all the beads down in the “tens”, making the digit a 0.

In the ones column, 5 + 8 equals 13, so you’ll carry a 1 over to the “tens” column, changing the digit there from 0 to 1. Push the top row bead up in the “ones” column, and three beads up from the bottom, making the “ones” column digit a 3.

4. Read the columns to get the answer

To recap, you now have a 7 in the “thousands” column, an 8 in the “hundreds”, a 1 in the “tens”, and a 3 in the “ones”: 2,145 + 5,668 = 7,813.

5. Subtract by doing the process in reverse

Now let’s subtract 788 from 845. Enter 845 on the abacus and start subtracting from the largest place value column, and borrow digits from the previous column instead of carrying them over.

7 from 8 is 1, so move the top row bead up and leave a single bead from the bottom row up in the hundreds place.

In the tens place, you can't subtract 8 from 4, so you'll borrow the 1 in the hundreds place (leaving it zero) and subtract 8 from 14, making it 6 in the tens place (one bead down in the top row and one bead up in the bottom row).

Do the same in the ones place, "borrowing" a bead from the tens place, making the tens place go from a 6 to a 5. Subtract 8 from 15, making the ones place a 7.

Mental Calculation Using Soroban

Visualizing a soroban is used for mental math. In the soroban method of mental calculation, the right brain memorizes the patterns of answers processed. In this method, answers are stored in the long-term memory as intuitive images. The memorization method (which uses the left brain) that is commonly utilized for examinations only uses the short-term memory. The Soroban (1 top bead and 4 lower beads) is the only abacus used to visualize the beads to calculate mentally. In the hands or mind of a skilled user, it can still beat a calculator.

Benefits of Learning Soroban

The society in general still values soroban skills. This is shown by the thousands of students who learn the soroban. A high value is placed on the benefits of the soroban, which are listed below:

Fosters a greater sense of numbers.
Helps develop an intuitive understanding of numbers through their concrete representation on the soroban (similar to Roman numerals).
Fosters one's trust in the process of calculation by enabling one to observe it in action.
Manifests the concept of decimal places and the progression of units by tens physically.
Instantly accomplishes addition and subtraction when numbers are placed on the abacus.
Improves understanding of compounded numbers (through the use of supplementary numbers for 5 and 10).
Helps in developing the beneficial qualities of concentration, patience, and endurance.
Fosters one's confidence in calculation.
Uses a left-to-right calculation method, which makes quick estimation and rounding off possible.
Works on the decimal rather than the fractional system, an easy progression to digital systems.
Develops mental calculation, which is the ultimate resource.
Develops the right brain tremendously.
Leads to greater mental capacity.
Expresses large numbers simply and easily.
Provides a sense of achievement as one's proficiency improves.

Japanese Abacus for Children

The Japanese abacus is specially designed for children because it is simple and logical. With one upper bead and four lower beads on each rod, it matches the base-10 system perfectly. Regular practice improves concentration, memory, and mental math skills, making it an excellent learning tool for young learners.

Learn Soroban Step by Step

Learning Soroban step by step starts with understanding its parts, such as rods, beads, and the horizontal bar. Beginners first learn how to show numbers from 1 to 9, then move on to larger numbers using place values like tens and hundreds. After this, simple addition and subtraction are practiced, followed by multiplication and division at higher levels. Step-by-step learning helps children build confidence and accuracy.

Modern Use of Soroban:

In modern times, the Soroban is widely used as an educational tool to develop mental arithmetic, concentration, and memory. It is popular in abacus training centers and international competitions, and many learners use it to visualize calculations mentally, even without the physical abacus.

Soroban in Japanese Schools:

In Japanese schools, the Soroban is taught as part of mathematics education, especially at the primary level. It helps students build a strong understanding of numbers, place value, and mental math skills, and continues to be valued despite the availability of digital calculators.

Conclution

The Japanese are said to be good at mental calculation. It’s because the simplicity of the Japanese number notation helps to deal with calculations and has taken deep roots in the Japanese mind. The soroban has been used for more than 400 years in Japan. We could conclude that the Japanese number system is the most suitable one for working with the soroban, and the soroban can be called a tool that expresses the Japanese culture of numbers.

FAQs

Q1: What is the Japanese Abacus (Soroban)?

The Japanese abacus, known as the Soroban, is a traditional calculating tool used in Japan. It helps in performing arithmetic operations and is also used to develop mental math skills, concentration, and number sense.

Q2: How is Soroban different from other abacuses?

The Soroban has a simple structure with one upper bead and four lower beads on each rod. This design directly matches the base-10 system, making calculations faster and easier than other abacuses like the Chinese Suanpan.

Q3: How does Soroban represent numbers?

Numbers are represented by moving beads toward the horizontal bar. Only the beads touching the bar are counted, and each rod shows a specific place value,e such as ones, tens, or hundreds.

Q4: How is zero shown on the Soroban?

Zero is shown when no beads on a rod touch the horizontal bar. This clearly represents zero and helps learners understand place value.

Q5: Can children learn Soroban easily?

Yes, Soroban is very suitable for children because it is visual and hands-on. It helps young learners understand numbers, counting, and basic calculations in a fun and interactive way.

Q6: What calculations can be done using Soroban?

Using the Soroban, learners can perform addition, subtraction, multiplication, and division accurately and efficiently.

Q7: Is Soroban still used in modern times?

Yes, Soroban is still taught in Japanese schools and used worldwide in abacus training centers and mental math competitions.

Q8: How does Soroban help in mental math?

With practice, learners start visualizing the Soroban in their mind, which helps them perform calculations mentally without the physical abacus.