This is a soroban. A wooden frame holding a row of vertical rods, with beads that slide up and down. There is no screen, no battery and nothing written down — once you know what the beads mean, the frame does the remembering for you. You read it left to right, exactly like a number on paper. The Chinese suanpan is the same idea with an extra bead in each deck.
Beginner walkthrough
How to use an abacus
A hands-on tour of the soroban, from the frame in front of you to carrying and borrowing. Twenty short chapters, a real abacus you can touch, and an explanation beside every move. No signup, no app, nothing to install.
The parts of an abacus
Try it, one move at a time
The frame is showing 0.
The whole walkthrough
Part one — the instrument
A bead counts only while it touches the bar. That horizontal strip across the middle is the reckoning bar, and it is the most important part of the instrument. Push a bead against it and the bead is switched on. Push it away and it is switched off. Everything else on this page follows from that one sentence.
One rod holds one digit. Each vertical rod carries a single digit from 0 to 9, so three rods show any number from 0 to 999 — the same way three boxes on paper would. When a rod fills up you move a bead on the rod to its left. Nothing happens automatically: you do the carrying, with your finger. That is the part your brain is learning.
The bead above the bar is worth 5. There is exactly one of them on each rod, and it switches on by sliding DOWN to meet the bar. The frame is showing 5 right now — one bead, one movement, no counting. This is why adding 5 on an abacus is faster than adding 1.
The beads below the bar are worth 1 each. There are four of them, and they switch on by sliding UP. Three are raised here, so this rod reads 3. Count them again: four, not five. That missing fifth bead is the reason the rest of this walkthrough exists.
Start from a loaded frame. This rod is showing 7 — the heaven bead down, two earth beads up. Before any new calculation you clear the abacus, which means putting every bead back where it started.
Zero is a position, not an absence. The beads did not go anywhere. The heaven bead went back up, the earth beads went back down, and nothing is touching the bar — so the frame reads 0. On a real soroban you clear it by tilting the frame and running a finger along under the bar. Always start from cleared.
The same bead is worth 1, 10 or 100. One earth bead is raised on each of the three rods, and the frame reads 111. Identical beads, identical movement, three different values — because value comes from WHICH rod a bead sits on. The rightmost rod is always the ones.
Every third rod is marked. A real soroban has a small dot on every third rod, and this one tints them instead. The marks group the rods into threes — ones, thousands, millions — the same job the commas do in 1,000,000. Pick whichever marked rod you want to be the ones, and the rest follow.
Part two — putting numbers on it
Thumb pushes up, index finger pushes down. Earth beads go UP with your thumb and come back down with your index finger. The heaven bead is the index finger both ways — down to switch it on, up to switch it off. It feels fussy for about a day, then it disappears, and it is what eventually lets a trained hand move faster than you can say the numbers.
Small digits are earth beads only. For 1, 2, 3 or 4 you just push that many earth beads up with your thumb. This rod shows 3. There is nothing clever here yet — you are literally counting beads.
Five is one bead, not five. The earth beads have gone back down and the heaven bead has come down to the bar. That is 5 — a single movement of a single finger. This is the first moment the abacus is faster than counting.
Six to nine is 5 plus the rest. Bring the heaven bead down for the 5, then push up as many earth beads as you still need. Here that is 5 + 2 = 7. Every digit from 0 to 9 is built exactly this way, which is the whole reason a rod needs only five beads instead of nine.
Start from the highest place, on the left. To set 472, the hundreds rod goes first: four earth beads up. Working left to right matches how you say and read the number, and it is the habit that stops you losing a digit in longer sums.
Then the tens. The middle rod needs 7 — heaven bead down for 5, then two earth beads up. The frame now reads 470. Notice each rod is set independently; they do not interact until you start calculating.
Then the ones, and it is done. Two earth beads on the right-hand rod and the frame reads 472. Three rods, three digits, in the order you would read them aloud.
Now read the beads instead of setting them. The digit row is switched off on purpose — this is the opposite skill, and it is the one that actually leads to mental arithmetic. Heaven bead down is 5, one earth bead up is 1, and nothing on the other rods. So the frame reads 6.
Watch for a heaven bead away from the ones rod. The middle rod has its heaven bead down. On the tens rod that is not 5 — it is 50. Two earth beads on the hundreds rod make 200, and the ones rod is empty. The frame reads 250. This is the pattern beginners misread most often.
An empty rod in the middle is a zero. Four earth beads on the hundreds rod, nothing at all on the tens, heaven plus two earth on the ones. That middle rod is not skipped — it is a zero holding the place open. The frame reads 407, not 47.
Part three — moving the beads
Start with 1 on the rod. One earth bead up, three still resting below. We are going to add 2. 1 + 2 = 3
The beads you need are free, so just move them. Two more earth beads up with your thumb, and the rod reads 3. This is a direct move: when there are enough beads sitting free, addition really is just sliding them. Most of arithmetic on an abacus is this. 1 + 2 = 3
Now add 5 to 13. The ones rod is showing 3, and its heaven bead is still up and unused. 13 + 5 = 18
Adding 5 is one finger. The heaven bead comes down and the frame reads 18. You did not touch a single earth bead — this is why 5 is a cheap number to add on an abacus and an expensive one to add on your fingers. 13 + 5 = 18
Subtraction is the same rule in reverse. The rod shows 8 — heaven bead down, three earth beads up. We are going to take away 3. 8 − 3 = 5
Push the beads back away from the bar. Three earth beads go back down with your index finger and the rod reads 5. The heaven bead never moved. Taking away is switching beads off, exactly as adding was switching them on. 8 − 3 = 5
Two rods at once: 47 − 25. Work one rod at a time and it stays easy. The ones rod shows 7 and needs to lose 5; the tens rod shows 4 and needs to lose 2. 47 − 25 = 22
Each rod handles its own digit. The ones rod sends its heaven bead back up (7 − 5 = 2) and the tens rod drops two earth beads (4 − 2 = 2). The frame reads 22. The rods did not talk to each other, because nothing needed to be carried. 47 − 25 = 22
Try to add 3 to this. All four earth beads are already up. There is no fifth bead to push, and yet 4 + 3 = 7 is obviously a real sum with a real answer. Reach for the bead that is not there — that feeling is the entire reason the next technique exists. The heaven bead is still free, and it is worth 5. 4 + 3 = ?
You have too much, so use it and give some back. You cannot add 3 directly. But you CAN add 5, and 5 is 2 more than 3 — so add the 5 and then take the extra 2 away. We call 2 the small friend of 3, because 3 + 2 = 5. 4 + 3 = 7
First add 5. The heaven bead comes down and the rod jumps to 9. That is too high by exactly 2, and it is too high on purpose. 4 + 5 = 9
Then take the small friend back. Two earth beads go back down and the rod settles on 7. You added 3 without ever having three free beads. Every 5-complement move is this shape: add 5, subtract the small friend. 9 − 2 = 7
Now try to add 3 to 9. This time the rod is completely full — heaven bead down, all four earth beads up. There is no spare 5 to borrow against, because you already used it. 9 is as high as a single rod can go, so the answer has to come from the rod on the left. 9 + 3 = ?
Ten lives on the next rod. Adding 3 means adding 10 and taking 7 back, because 3 + 7 = 10. We call 7 the big friend of 3. The 10 goes on the rod to the left; the 7 comes off this one. 9 + 3 = 12
Take the big friend off this rod. Removing 7 from 9 means the heaven bead goes back up and two earth beads come down, leaving 2. The rod is suddenly nearly empty, which always looks wrong the first time. 9 − 7 = 2
Then carry the 1 to the left. One earth bead up on the tens rod and the frame reads 12. That is the carry — done with your finger, on the rod next door. Every 10-complement move is this shape: subtract the big friend, add 1 to the left. 2 + 10 = 12
Borrowing is carrying, run backwards. The frame shows 11 and we need to take 7 away. The ones rod is showing 1, so there is nothing like 7 to remove from it. 11 − 7 = 4
Take the 10 from the left rod first. One earth bead goes back down on the tens rod and the frame reads 1. You have now removed 10, which is 3 more than the 7 you actually wanted to remove. 11 − 10 = 1
Then give the big friend back. Three earth beads up on the ones rod and the frame reads 4. Same pair of numbers as before, opposite directions: to subtract 7, take 10 and give back its big friend 3. 1 + 3 = 4
Sometimes both friends fire at once. The frame shows 6 and we are adding 7. The big friend of 7 is 3, so the move is: take 3 off this rod, then carry 1 to the left. But look at the ones rod — it has only one earth bead up, so taking 3 off it is itself a problem. 6 + 7 = 13
Take 5 off first. To subtract 3 you use the small friend: send the heaven bead back up (that is −5) and the rod drops to 1. You have taken away 2 too many, which the next step fixes. 6 − 5 = 1
Give the small friend back. Two earth beads up and the rod reads 3. Between them, those two moves subtracted exactly 3 — the big friend of 7 — using the 5-complement to get there. 1 + 2 = 3
Now carry the 1. One earth bead up on the tens rod and the frame reads 13. Three finger movements for 6 + 7, and both techniques in a single sum. This is where Elementary B begins, and where the abacus stops being a counting toy. 3 + 10 = 13
The frame is yours now. Five rods, digits on, nothing locked. Set a number, add to it, take from it, and clear it when you want to start again. When you want problems to work on, Guide Me will solve any equation bead by bead, and the practice drills will time you.
The complements, in one table
Two pairs of numbers do all the work. The small friend of a number is what it needs to reach 5; the big friend is what it needs to reach 10. Learn these nine rows and the rest of the abacus is bookkeeping.
| Number | Small friend (to 5) | Big friend (to 10) |
|---|---|---|
| 1 | 4 | 9 |
| 2 | 3 | 8 |
| 3 | 2 | 7 |
| 4 | 1 | 6 |
| 5 | — | 5 |
| 6 | — | 4 |
| 7 | — | 3 |
| 8 | — | 2 |
| 9 | — | 1 |
Common questions
What are the parts of an abacus called?
The wooden case is the frame, the horizontal strip across the middle is the reckoning bar (or beam), and the vertical wires are rods — one rod per digit. Above the bar sits a single heaven bead worth 5; below it are four earth beads worth 1 each. A bead counts only while it is touching the bar.
Which fingers do you use on an abacus?
Earth beads go up with the thumb and come back down with the index finger. The heaven bead is moved by the index finger in both directions. Proper finger technique feels awkward for a day or two and then disappears — it is what eventually lets a trained hand calculate faster than you can say the numbers aloud.
How do you read a number on an abacus?
Read left to right, one rod at a time, and count only the beads touching the bar. On each rod, a lowered heaven bead is 5 and each raised earth bead is 1, so a rod showing heaven plus two earth beads is 7. A rod with nothing against the bar is a zero and still holds its place.
What are small friends and big friends?
They are the complement pairs that make abacus arithmetic work. A small friend is what a number needs to reach 5 (3 and 2 are small friends), and a big friend is what it needs to reach 10 (3 and 7 are big friends). When there are not enough beads to add a number directly, you add 5 or 10 instead and take the friend back off.