Flash Anzan — Free Online Speed Addition Trainer
Numbers flash. You add them. That's it.
- Mental math
- 4 min
- Hard
Flash Anzan comes from competitive soroban (abacus) training in Japan. Digits appear one at a time, far too fast to say out loud, and you add them as they go. The trick that expert practitioners use is to stop verbalising entirely and move the beads visually instead.
Play Flash AnzanHow it works
1Digits flash one at a time, in the same spot.
2Add each digit as it lands — do not wait for the end.
3Type the sum. Three in a row levels you up.
How to play
- 1
Digits flash
A short series of numbers appears one at a time in the same spot on screen.
- 2
Keep a running total
Add each digit as it lands. Do not try to memorise the list and add at the end — that fails by about level 4.
- 3
Type the sum
Enter the total when prompted. Three correct answers in a row moves you up a level; the digits get faster and more numerous.
What it trains
Compute fast without writing anything down. Trained abacus users process numbers through a visuospatial route rather than a verbal one, which is why the digits can outrun inner speech.
- Brain area
- Inferior parietal lobule
- Based on
- Hatano & Osawa, 1983
Leaderboard
Weekly season resets every Monday. Scores show as Lvl 5.
Leaderboard
Questions
How fast do the numbers go?
Level 1 gives you about a second per digit. By level 10 you are under 400ms, which is faster than you can say the numbers to yourself.
What's a good level to reach?
Most people plateau around level 5–7. Level 10+ generally means you have stopped subvocalising and started seeing the numbers.
Do I need to know how to use an abacus?
No. The game works with ordinary mental addition — abacus training just happens to be the fastest known route to the top levels.
