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🧮 What Is a Soroban? The Japanese Abacus Explained for Parents
A soroban is the Japanese abacus. It looks simple — a wooden frame, a bar across the middle and columns of beads — but it is one of the most powerful tools ever made for understanding numbers. It is the abacus used by almost every modern "abacus mental math" programme, and it is the one BeadBop teaches.
The parts of a soroban
- Rods: the vertical wires. Each rod is one place value — ones, tens, hundreds and so on, from right to left.
- Beam (reckoning bar): the horizontal bar. Beads only count when they are pushed against the beam.
- Heaven bead: the single bead above the beam. It is worth 5.
- Earth beads: the four beads below the beam. Each is worth 1.
- Unit dots: small dots on the beam every third rod, to help you find the ones, thousands and millions rods quickly.
How to show a number
Every digit from 0 to 9 can be made on a single rod. 0 to 4 use only earth beads. 5 is the heaven bead alone. 6 to 9 are the heaven bead plus one to four earth beads.
| Digit | Heaven bead | Earth beads |
|---|---|---|
| 3 | up (not counted) | 3 pushed up |
| 5 | down (5) | none |
| 8 | down (5) | 3 pushed up |
| 9 | down (5) | 4 pushed up |
For bigger numbers, use more rods: 47 is 4 on the tens rod and 7 on the ones rod. Numbers are always set from left to right, just as you read them.
Soroban vs. other abacuses
The Chinese suan pan has two beads above the beam and five below. The Russian schoty has ten beads on each wire and no beam. The Japanese soroban settled on one-and-four around 1930, because that layout has exactly one way to show each digit — which makes it faster and easier to picture in your head.
Why the soroban is used for mental math
Because every number has one clear bead picture, children can learn to see the soroban in their mind. After enough practice they "move" imaginary beads to calculate — a skill called anzan. Read more in our Flash Anzan guide.
Quick answers
Is a soroban the same as an abacus?
A soroban is one kind of abacus — the Japanese one, with one bead above the beam and four below.
What is the heaven bead worth?
The single bead above the beam is worth 5. Each of the four beads below is worth 1.