How to read a Japanese abacus
Start at the right. The first rod is ones, the next is tens, and the next is hundreds. On each rod, the upper bead counts as five and each lower bead counts as one. A bead counts when it moves toward the middle bar.
Try building 47
- Choose Explore and press Clear.
- On the tens rod, move four lower beads toward the bar. They are worth 40.
- On the ones rod, move the upper bead and two lower beads toward the bar. They are worth 7.
- Check the display. It should show 47.
Soroban practice for home or class
Use Learn for guided practice or Quiz to check understanding. For a quick classroom activity, turn on Hide number, build 47, and ask learners to read the beads before revealing the answer. Compare 47 with 74 and ask what changed.
Continue with the Number Builder Challenge or browse more digital maths tools.
How to Add, Subtract, Multiply and Divide on the Soroban
Choose Explore and press Clear. The rightmost rod shows ones, then tens and hundreds to its left. On each rod, the upper bead counts as 5 and each lower bead counts as 1. Beads count when they move toward the middle bar.
Addition
21 + 3. Set 2 tens and 1 one. Move three more lower beads toward the bar on the ones rod. The display shows 24.
4 + 2. There aren’t two more lower beads available. Move the upper bead toward the bar to add 5, then move three lower beads away to take away 3. You’ve added 2 because 5 − 3 = 2. The display shows 6.
8 + 4. Add 1 on the tens rod, then take away 6 on the ones rod by moving the upper bead and one lower bead away. This works because 10 − 6 = 4. The display shows 12.
Subtraction
38 − 3. Set 3 tens and 8 ones. Move the three active lower beads on the ones rod away from the bar. Leave the upper bead in place. The display shows 35.
32 − 7. Remove 1 ten, then add 3 ones. To change the ones rod from 2 to 5, move the two lower beads away and move the upper bead toward the bar. You’ve taken away 7 because 10 − 3 = 7. The display shows 25.
Multiplication by repeated addition
3 × 4. Think of it as three groups of four. Start at 0 and add 4 for each group. The display goes 4 → 8 → 12. The answer is 12.
Division by repeated subtraction
14 ÷ 4. Set 14 and take away 4 each time. The display goes 14 → 10 → 6 → 2. Count the subtractions as you go. You made 3 full groups, with 2 left over. The answer is 3 remainder 2. The display tracks what is left, and you keep track of the number of groups.
Your turn
Try 23 + 11, 41 − 6, 4 × 3, and 17 ÷ 5. Read each answer aloud and explain which beads you moved.
Check your answers. 34, 35, 12, and 3 remainder 2.
Japan Soroban Museum’s addition and subtraction guide · Japan Society’s Soroban teaching notes
Frequently Asked Questions (FAQ)
What is a Soroban?
A Soroban is a Japanese abacus used for arithmetic calculations. It consists of rods with upper and lower beads representing numerical values.
Is this Soroban free to use?
Yes. The tool is completely free and works directly in your web browser.
Can children use this tool?
Absolutely. It is designed to be simple, visual, and easy for young learners.
Does the tool work on mobile devices?
Yes. The responsive design works on smartphones, tablets, laptops, and desktop computers.
Can I learn mental math using Soroban?
Yes. Regular practice with a Soroban helps develop strong mental calculation and visualization skills.
What mathematical operations can be practiced?
You can practice:
- Number representation
- Place value
- Addition
- Subtraction
- Multiplication
- Division
- Mental arithmetic