[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"content-seo:flashMentalMath":3},{"description":4,"seo":5,"faq":8},"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.\n\nDifficulty 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.\n\nOne 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.",{"ogTitle":6,"ogDescription":7},"Flash Anzan Online | Flash Mental Math Game - Giggleus","Numbers flash for under a second, then vanish. Add them in your head and type the total, with one more number every two levels. How many rounds can you clear?",[9,12,15,18],{"question":10,"answer":11},"How do you play flash anzan?","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.",{"question":13,"answer":14},"How does the difficulty increase?","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.",{"question":16,"answer":17},"What changes in Add & subtract mode?","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.",{"question":19,"answer":20},"How are the score and brain age calculated?","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."]