Two screens, one abacus

Share a live abacus

Start a session, send the code, and whoever joins sees your beads move as you move them. Hand them control when you want them to try it themselves, and take it back with one tap.

Free, no signup, works on a phone

Start a session

You will get a code to share. You stay in charge of who joins and who can move the beads.

Rods

or

Join a session

Got a code from a teacher or a parent? Enter it here.

The person who invited you can see every bead you move.

Loading abacus…

How it works

Three steps, no accounts

  1. 1

    Start a session

    Pick how many rods you want and start. You get a five-character code and a link to send — nothing to install and nobody to sign up.

  2. 2

    Let them in

    When someone enters your code you get asked before they see anything. Until you say yes, they cannot see the frame at all.

  3. 3

    Show, then hand over

    They watch your beads move in real time. Tap Allow control when you want them to try it, and take it back the moment you want the frame to yourself again.

Why watching beads move matters

Bead technique is a motor skill before it is an arithmetic one, and it is almost impossible to correct from a photograph. A learner who lowers the five bead with the wrong finger, or who clears a rod in two motions where one would do, looks exactly right in a still image and wrong the moment you watch them work. A live frame shows the motion, which is the part that actually needs fixing.

Who this is for

A tutor working with a student who is not in the room. A parent who learned on a physical soroban and wants to show a child what a proper finger movement looks like. A teacher taking two students back to back on the same link. The session needs no account on either side, so it works with whoever you are talking to right now.

Who can move the beads

You start with control and the other side starts watching. Hand control over when you want them to try something themselves, and take it back when you want to demonstrate again. Control is enforced on our server, not just hidden in the page, so a viewer cannot move your beads by fiddling with the browser.

What is stored

Nothing. A session lives in memory for as long as it runs and disappears when it ends — there is no recording, no transcript and no account to attach one to. The code stops working when the session finishes, and there are no names anywhere in it.

Common questions

Do we both need an account?
No. Neither side signs up and neither side installs anything. One person starts a session, sends the five-character code or the link it generates, and the other opens it in a browser. There is nothing to create, nothing to log into and nothing to remember afterwards.
Can the other person move my beads?
Only if you allow it, and only for as long as you allow it. Whoever joins starts as a watcher; you hand control over with one tap when you want them to try something, and take it back the same way. The permission is enforced on our server rather than hidden in the page, so a viewer cannot move your beads by editing the browser.
What happens if I send the code to the wrong person?
Nobody sees your frame until you let them in — entering a valid code only puts someone at the door, and until you say yes they get no beads, no number and no rod count. If somebody is already in the session you can remove them, which invalidates their seat and changes your code, so the link you sent stops working while you keep the session you are running.
How long does a session last?
Up to ninety minutes, sized to cover a lesson rather than a game. It also ends early if nobody is watching it, so a session left open in a forgotten tab does not sit there holding a code. When it ends both sides are told why instead of being left with a frozen frame.
Does it work on a phone?
Yes, on both sides, and the two do not have to match — a tutor on a laptop with a student on a phone is the ordinary case rather than the awkward one. The abacus is the same bead engine the Kani Math app uses, including the drag behaviour and the keyboard controls, so nothing about the frame is a cut-down version.
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