ANZAN is MIKIRI's flash mental math game. Numbers appear one after another in the same spot, each for a fraction of a second. When the last one has gone, you type the total and press OK.
It follows the format of flash anzan, the timed mental-arithmetic drill familiar from abacus schools in Japan. You cannot write anything down or look back, so you have to keep a running total while the next number is already arriving. Each round makes one thing harder — more numbers, faster numbers or more digits — and a miss shows the full sum so you can see where it slipped.
▶ ANZAN — Play free nowRound 1 is three 1-digit numbers at 0.9 seconds each. Round 13 (elite) is seven 1-digit numbers at 0.45 seconds, round 14 moves to 2-digit numbers, round 21 (demon) is seven 2-digit numbers at 0.35 seconds, and round 28 (beyond human) moves to 3-digit numbers. Each number stays on screen for at least 0.3 seconds, and the colour alternates so repeated values are still visible as new numbers.
The hard part of flash mental math is not the addition itself but holding the running total while the next number arrives. Single-digit sums are easy; keeping them going without a break is not.
You only ever see one number and cannot look back. Read it, update the total, get ready for the next — if that flow stops once, the remaining numbers stop going in.
Trying to remember the numbers. Three is manageable; beyond five there is no time. Keep only the total.
Missing a repeated number. The colour alternates, so the same value twice in a row still counts twice.
Adding two digits at once. Add the tens, then the ones, and carrying mistakes drop.
Each number stays for at least 0.3 seconds and there is no full-screen flashing. The fast rounds are still demanding, so leave gaps between sessions.
People with abacus experience can improve a lot by visualising beads. Because that background shifts results so much, compare yourself with your own last run rather than with others.