Drag-to-set beads
Beads track your finger 1:1, snap to the right value on release, and ride in stacks the way a real soroban does. Touch and mouse both work.
A free virtual soroban abacus in your browser.
Drag the beads right here — the same wooden-frame soroban our students use, with up to 15 rods, shareable frames, and keyboard input. No signup, no install, free forever.
Style
Built for actual practice, not a screenshot demo.
3 to 15 rods
Start narrow for first lessons or go wide for multi-digit drills. The thousands rod is tinted so kids spot the separator at a glance.
Show or hide digits
Toggle the digit row below each rod on and off — perfect for self-check during practice, or to hide and read the value mentally first.
Works everywhere
Web, mobile, tablet. The frame adapts to your screen and the rod count auto-caps on narrow phones so every bead stays in view. No account, no install, no tracking.
Working with this tool
- 1
Move the beads
Click or drag a bead toward the middle bar to switch it on, and away from the bar to switch it off. Touch drag works exactly like mouse drag, and double-tapping a rod label clears that rod.
- 2
Pick your width
Choose anywhere from 3 to 15 rods. Three rods is plenty for a first lesson; fifteen lets you build numbers all the way into the trillions.
- 3
Show or hide the digits
Keep the digit row visible while you learn to read the beads, then hide it and read the value from the frame alone — that is the first step toward mental math.
- 4
Share the frame
The Share button copies a link that encodes the number currently on the rods and the rod count, so a teacher can hand a student an exact starting position.
Why mental arithmetic matters
Working the beads forces a student to break every number into base-10 parts — the mental step a calculator skips. With practice, students learn to picture the soroban and compute multi-digit arithmetic entirely in their head, a technique known as anzan. The full Kani Math program builds that skill across nine levels of lessons, drills and competitions.
What is a soroban?
The bead frame above is a Japanese soroban — one heaven bead per rod above the divider, four earth beads below. That 1+4 layout is what separates the modern soroban from the older Chinese suanpan (2+5). Fewer beads, faster math.
Japan has taught the soroban in elementary school for over a century, and still does — because the same clean layout that speeds up addition is also what lets a trained student picture the abacus in their head. That mental image is the foundation of mental arithmetic, and the reason a soroban graduate can outrun a calculator on multi-digit sums.
One instrument, many names
The bead frame on this page goes by a different name almost everywhere it is used. In Japan it is the soroban, the 1+4 layout we teach. In China it is the suanpan, an older 2+5 design with an extra bead above and below the beam. French speakers call any bead calculator a boulier, and across Spain and Latin America it is the ábaco.
Whatever you call it — soroban, suanpan, boulier, or ábaco — the idea is the same: numbers become bead positions your fingers and eyes can work with directly. This free virtual abacus follows the Japanese soroban layout because it is the one modern mental-arithmetic programs are built on, but anyone who learned on a suanpan or a school boulier will feel at home in seconds.
Virtual abacus — common questions
What is an abacus?
The soroban is a Japanese abacus with one bead in the upper deck ("heaven", worth 5) and four beads in the lower deck ("earth", each worth 1) on every rod. Slide beads toward the middle beam to count them. Each rod represents a place value — ones, tens, hundreds, and so on.
How do I use it?
Click or tap a bead to move it. The heaven bead toggles between active (down, adds 5) and idle (up, adds 0). Earth beads slide up toward the beam to be counted. The number above each rod shows the current digit.
How many rods does the online abacus have?
The Kani Math online abacus supports 3 to 15 rods. Desktop users can pick up to 15 rods — enough for a 15-digit number. Mobile users are capped at 12 rods in landscape and 6 in portrait so the bead row stays touchable inside a phone-sized stage.
Are there keyboard shortcuts?
Yes. Click a rod to focus it, then use 0–9 to set a digit, ↑/↓ to nudge it, Space (or H) to toggle the heaven bead, Backspace to clear, and +/- to adjust the whole number.
Does this work on a phone or tablet?
Yes. The layout adapts to phone portrait, phone landscape, tablet and desktop. Beads respond to touch drag exactly like mouse drag, and the rod count auto-caps on narrow screens so the frame stays easy to use.
Is this virtual abacus really free?
Yes — completely free, with no ads, no upsells, and no locked features. It is built by the Kani Math team as an open tool for students, parents, and teachers, and it stays free.
Where does my data go?
Settings are saved in your browser's local storage. Nothing is sent to a server, no account is created, and we don't track who uses the abacus. The only network call is a single anonymous analytics ping so we know how many people visit.
What is the difference between a soroban and a suanpan?
A Japanese soroban has 1 heaven bead and 4 earth beads per rod; the Chinese suanpan has 2 and 5. The extra suanpan beads suited older base-16 weight units, while the leaner soroban maps exactly to decimal digits — which is why modern mental-arithmetic training uses it.
Why does it help to practice with an abacus?
Moving beads forces you to internalize place value and decompose every number into base-10 parts. Students who train on a physical or virtual abacus eventually learn to visualize the beads and calculate entirely in their head — a skill called anzan, the basis of competitive mental-arithmetic programs.
What else does Kani Math offer?
Mental-arithmetic lessons across nine levels (Foundation through Grand), flash-number drills, head-to-head versus matches, classroom tools for teachers, and a galaxy-themed progression map for kids. Explore the full program at app.kani-math.com.
Keep practicing
Learn the techniques on the beads
The abacus above is the instrument; these pages teach what to do with it. Each one is a walkthrough — it explains a move, works it on a frame beside the text, then hands the beads back and asks you to set a number yourself. The problem sets come after, on the practice pages.
Want more than an abacus?
Lessons, flash drills, versus matches and a nine-level soroban curriculum — the full Kani Math program picks up right where this abacus leaves off.
- ✓Nine levels, from the first bead to division
- ✓Guided lessons that teach the technique, not just drills
- ✓Flash, listening and abacus drills at a speed you set
- ✓Versus matches against friends or the computer
- ✓Say your answers out loud — the app listens and marks them
- ✓Streaks, coins and badges, with parent and teacher views
Built and maintained by the Kani Math team. No ads. No upsells.