🧮 Soroban
Practice freely on the interactive Soroban — choose your column count and start clicking!
What is a soroban?
A soroban is a Japanese abacus: a rectangular frame with vertical rods, each holding one upper bead worth 5 and four lower beads worth 1. Each rod is one place value, so a soroban can show any whole number. Children use it to understand numbers, then to add and subtract and, with practice, to calculate mentally by picturing the beads (anzan).
The parts of a soroban
- The frame holds an odd number of vertical rods, often 13, 17 or 23 on a real soroban.
- The beam (reckoning bar) separates the upper deck from the lower deck. Only beads touching the beam count.
- The upper bead on each rod is worth 5. The four lower beads are worth 1 each, so one rod shows 0 to 9.
- Dots on the beam mark every third rod, which helps you find the ones place and read large numbers.
Read the full guide: history, benefits and the best age to start
How to use this online soroban
- Choose the number of rods with the slider. Three rods are enough to practice numbers up to 999.
- Only beads moved toward the middle bar count. On each rod, the upper bead is worth 5 and each lower bead is worth 1.
- Read place values from right to left: ones, tens, then hundreds. Click or drag the beads and check the displayed number.
Try 12 + 3 = 15
Clear the beads away from the bar. On the tens rod, move one lower bead toward the bar. On the ones rod, move two lower beads toward it: the value is 12. To add 3, replace the two lower beads on the ones rod with its upper bead. That rod now shows 5, so the total is 15. This uses the complement 3 = 5 − 2.
Check your understanding
Clear the abacus and represent 7, 24 and 105. For 105, the tens rod stays empty. If a number is wrong, check the place value and whether each bead touches the bar before trying again.