Abax

Learn the soroban move by move, then carry it in your head.

Abax is a soroban (Japanese abacus) trainer. It shows every bead move with the finger that makes it, drills each rule until it is quick, and then takes the beads away.

Download Read the manual

Linux, Windows, macOS and Android. MIT licence.

How it teaches

A lesson: the heaven bead to move is ringed in vermilion, with an arrow and the line 'Index finger: push the heaven bead down'.
Lessons explain one rule in plain words, then show it on the beads: the bead to move is ringed, with an arrow and the finger to use.
A drill item, 6 + 5 + 6, with the first number set on the soroban and a keypad below.
Drills are worked on the beads. Stall and the next move appears; get it wrong and the correct moves replay, in order.
Flash anzan: the number 90 shown large, second of three.
Flash anzan shows numbers one at a time, faster step by step. You add them on the soroban in your head.

A scheduler tracks each skill's knowledge, accuracy, speed and step. A session is a warm-up, a focus drill on the weakest skill and a cool-down. How the scheduler works.

The curriculum at a glance

Fifteen skills, all open, in any order. The suggested path is marked.

  1. Beads
    • S0 Read and set numbers
    • S1 Add directly
    • S2 Subtract directly
  2. Small friends
    • S3 Add through 5
    • S4 Subtract through 5
  3. Big friends
    • S5 Add through 10
    • S6 Subtract through 10
    • S7 Both at once
  4. Longer numbers
    • S8 Multi-digit addition
    • S9 Mixed chains
  5. Multiply and divide
    • S10 Multiplication
    • S11 Division
  6. In your head
    • A1 Anzan, fading beads
    • A2 Flash anzan, 1 digit
    • A3 Flash anzan, 2 and 3 digits

Each skill, its rule and its examples

Three finishes

Walnut finish: lacquered walnut frame, bamboo rods, bone beads.
Walnut bone beads, bamboo rods
Ebony finish: near-black frame, brass rods and beam, bone beads.
Ebony bone beads, brass rods
Maple finish: pale maple frame, steel rods, slate beads.
Maple slate beads, steel rods

Each in a light and a dark theme.

Download

The latest release is on GitHub.

Android 7.0 or newer. The desktop builds are not code-signed: on Windows choose "More info" then "Run anyway"; on macOS the app is ad-hoc signed but not notarized, so right-click it and choose Open the first time (macOS 15 and later: System Settings, Privacy & Security, Open Anyway), or run xattr -cr /Applications/Abax.app once. SHA256SUMS.txt lists the checksums. Install instructions.