Mini Games
Flash Mental Math
Numbers flash by one at a time — add them in your head and type the total. The flash anzan drill from abacus classes, in your browser.
How to play
- Press Start: numbers flash on screen one at a time and vanish.
- Add them up in your head, type the result and press ✓ (or Enter). There's no time limit for typing.
- Each round you clear brings more numbers, more digits or faster flashes. In Add & subtract mode, some numbers are taken away. One wrong answer ends the run.
My Best
---
How many rounds can you clear?
Mode
Ranking
| Rank | Nickname | Score |
|---|---|---|
| Rank | Nickname | Score |
|---|---|---|
- |  You | - |
Your record is only saved in this browser.
Records are not shared across different browsers or devices.
More brain games
Recommended Content
Free online word search puzzle. Find hidden words in the letter grid by dragging in any of 8 directions.
Guess the hidden 5-letter English word in 6 tries! Type a word and you'll see green, yellow, and gray hints. A new puzzle drops worldwide every midnight.
Guess the hidden 4-syllable Korean word in 6 tries! A Wordle-style puzzle for Hangul readers, with color hints for each syllable's initial consonant, vowel and final consonant.
See part of a flag and guess the country! A new tile reveals with each wrong guess. Solve it in 6 tries!
Solve as many 2–9 multiplication problems as you can in 60 seconds! Random time attack or single-table drill.
Solve as much arithmetic as you can in 60 seconds. How fast is your brain?
Deduce the computer's secret number from Strike and Ball hints in this classic logic game. 3-digit and 4-digit modes.
Sort 16 words into four hidden groups of four. One new puzzle a day; the fourth mistake ends the game.
Flash anzan is the mental-arithmetic drill used in abacus (soroban) classes: numbers appear on screen one at a time, vanish, and you give the total. This free browser version starts with three one-digit numbers shown for 0.8 seconds each, with a 0.2-second gap between them. You type the answer on the on-screen keypad or your keyboard with no time limit, and every correct answer takes you to the next level.
Difficulty climbs on three fronts. You get one more number every two levels (up to 15), two-digit numbers from level 4 and three-digit numbers from level 9, and each number stays on screen 0.04 seconds less per level, down to 0.26 seconds. The game also tracks how fast you answer: answer quickly and the flashes speed up a little more; take your time and they slow down slightly but gain an extra digit. Add & subtract mode mixes in minus signs, using numbers of the same size and never letting the running total drop below zero.
One wrong answer ends the run, and your score is the number of rounds you cleared, posted to the world ranking and shareable as a challenge link. The brain-age figure on the result screen is a playful conversion (0 rounds = 65, 20+ rounds = 18), not a measurement. For a timed test where each problem stays on screen, try the Mental Math Sprint.
Frequently Asked Questions
Q. How do you play flash anzan?
A. Numbers appear on screen one at a time and vanish; add them in your head, then type the total and press ✓ or Enter. Level 1 shows three one-digit numbers for 0.8 seconds each, and there's no time limit for typing.
Q. How does the difficulty increase?
A. You get one more number every two levels, up to 15, with two-digit numbers from level 4 and three-digit numbers from level 9. Display time drops by 0.04 seconds per level to a minimum of 0.26 seconds; if you answer slowly, numbers stay a little longer but gain a digit.
Q. What changes in Add & subtract mode?
A. From the second number on, each number carries a + or − sign, so some are subtracted. Subtracted numbers have the same number of digits, and the running total never drops below zero, so the answer is always a whole number of 0 or more.
Q. How are the score and brain age calculated?
A. One wrong answer ends the run, and your score is the number of rounds you cleared. Brain age simply converts that score from 65 (0 rounds) down to 18 (20+ rounds) for fun; it does not measure your brain.