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Japanese Abacus

Soroban
Wadi

The ancient Japanese technique that trains your brain to calculate faster than a calculator. Used in Japanese schools for 400+ years. Now available here — complete, step-by-step, from zero to mastery.

8

Lessons

40+

Steps

Free

Forever

Start Learning Now

Why Learn Soroban?

Faster than a calculator

Top-grade students add 15 five-digit numbers in under 5 seconds. No device needed.

Builds both brain hemispheres

Physical bead movement (left brain) + mental visualization (right brain). Proven to boost IQ scores.

Strengthens concentration

Flash Anzan training at 0.2 seconds per number requires extraordinary focus. This focus transfers to all subjects.

Used in Japan for 400 years

Taught in 1000+ Japanese schools today. Japanese students consistently top global math rankings.

4 Core Concepts

Heaven Bead (上珠)

ONE bead above the bar per column. Push DOWN = adds 5. Push UP = removes 5. Moved by index finger only.

Heaven bead DOWN → +5. Heaven bead UP → −5.

Earth Beads (下珠)

FOUR beads below the bar per column. Each bead pushed UP = +1. Moved UP by thumb, DOWN by index finger.

N earth beads UP → value N (where N = 0, 1, 2, 3, or 4)

Friends of 5 (5の補数)

When adding N would go past 4 (but not past 9): set heaven (+5), remove 5-friend from earth. This avoids ever needing more than 4 earth beads.

1↔4 | 2↔3 | 3↔2 | 4↔1 → pairs that sum to 5

Friends of 10 (10の補数)

When adding N would exceed 9 (column overflow): carry 1 to next column, subtract 10-friend from current column.

1↔9 | 2↔8 | 3↔7 | 4↔6 | 5↔5 → pairs that sum to 10

Live Demo — Type Any Number

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Gold beads = active (touching bar). Tan beads = inactive (away from bar).

Complete Learning Path

1

Abacus Structure

Heaven beads, earth beads, place values

2

Finger Technique

Thumb vs index, the critical pinch motion

3

Friends of 5

The first complement system (1↔4, 2↔3)

4

Friends of 10

Carry/borrow with 10-complement pairs

5

Subtraction

Direct, 5-friend, and borrow methods

6

Multiplication

Partial products, placement, carries

7

Division

Short and long division on soroban

8

Mental Abacus (Anzan)

Visualize and calculate without the physical board

Practice Modes

Step-by-Step Tutorial

START HERE

8 lessons · 40+ animated steps · Full method from basics to Anzan

Free Practice

Unlimited problems · Set your own difficulty · Track accuracy

Flash Anzan

ADVANCED

Numbers flash on screen · Mental calculation speed challenge · 6 levels

Recommended Practice Schedule

Week 1–2

Structure + Fingers

15 min/day. Master bead positions and the 4/5 pinch exchange.

Week 3–4

Friends of 5

20 min/day. All four 5-friend cases until they are automatic.

Week 5–6

Friends of 10

20 min/day. Carry recognition + 4 addition cases.

Week 7–8

Subtraction

20 min/day. All borrow cases, mixed problems.

Month 3+

Flash Anzan begins

30 min/day. Start mental visualization. Do not skip physical practice.

Quick Reference — Finger Strokes

THUMB

Push earth beads UP

Adding 1, 2, 3, or 4

INDEX

Push heaven DOWN (adds 5)

Adding 5 to any digit

INDEX

Push heaven UP (removes 5)

Subtracting 5 or breaking above-5 values

INDEX

Push earth beads DOWN

Subtracting 1–4

PINCH

Heaven down + Earth down simultaneously

The 4→5 exchange (most important motion)