Game Guide
How to play Shuzan in MyRin: solve falling equations before they land, which one to answer first, soroban number tricks, and the rules for each difficulty.
Shuzan gives you a simple deal: equations fall from the top of the board, and you have until they land to answer them. On easy that is a relaxed warm-up. On hard, with four equations arriving in staggered waves, it becomes a test of triage as much as arithmetic. This guide covers how Shuzan works on each difficulty, which equation to answer first, and the soroban habits that make the arithmetic itself faster.
Each equation falls inside a circle. You answer by tapping the correct number from the buttons at the bottom of the screen, which resolves the matching circle. Easy drops one circle at a time, medium drops two simultaneously, and hard launches four in staggered waves. The objective is to resolve as many equations as possible without missing more than four.
That last rule shapes everything. Four misses are a budget, not a failure. A player who treats every circle as sacred panics on hard; a player who spends the budget deliberately keeps going.
The soroban reached Japan from China, where the larger suanpan was used, and became the everyday calculating tool of merchants and schools for centuries. The modern Japanese soroban has one bead above the bar and four below on each rod, so every digit from 0 to 9 is a combination of one "five" bead and up to four "one" beads.
Experienced users eventually stop needing the physical frame. They calculate on an imagined abacus, a skill called anzan (暗算), and move the beads in their mind. Frank and Barner studied children trained this way in India and found that their mental abacus is stored in visual working memory, column by column, and that their calculation was relatively insensitive to verbal interference, unlike untrained children (Journal of Experimental Psychology: General, 2012).
Shuzan does not ask you to learn the abacus. It borrows the idea that matters for the game: numbers handled as quick visual chunks rather than spoken step by step.
On medium and hard, the order in which you answer matters more than your speed on any single sum. A simple rule works for almost every situation:
Keep a running count of your misses. With zero or one used, you can afford a sacrifice. With three used, every circle matters and you answer strictly lowest first.
Abacus training teaches a handful of number habits that transfer directly to Shuzan, even without an abacus in your hands:
None of these needs practice outside the game. Pick one habit per session and apply it deliberately for a few levels; within a week it stops being a trick and becomes the way you see the numbers.
Arithmetic Blitz, the sprint version of mental math in MyRin, runs free in your browser with no account.
Play Arithmetic Blitz freeArithmetic Blitz is a sprint: one problem at a time, as many as you can solve before the clock runs out. Shuzan is parallel. From medium upwards you hold several equations in view, decide which to solve, and switch between them while they move. That adds two demands on top of arithmetic fluency: divided attention across several targets, and prioritisation under time pressure.
Both depend on processing speed, the rate at which you take in simple information and act on it, which is covered in more depth in processing speed and brain training. As with any brain game, expect to get much better at Shuzan and somewhat better at mental arithmetic in general; broad claims beyond that are not supported by the research.
Shuzan is the Japanese calculation tradition compressed into a few minutes of play. For the story of the soroban and the other games MyRin draws from, see The Mind Games of Japan, and for the full game list, the MyRin games page. MyRin is free on iOS and Android with 30 games and 18,000 levels.
Shuzan is a mental arithmetic game in MyRin. Equations fall from the top of the board inside circles, and you answer each one by tapping the correct number before it lands. The run ends when you miss more than four equations. The name is the Japanese word for calculating on the soroban, the Japanese abacus.
It depends on the difficulty. On easy, one circle falls at a time. On medium, two fall simultaneously. On hard, four are launched in staggered waves, so you are always reading one equation while another is already on its way down.
Answer the one closest to the bottom, unless it is so hard that it would cost you two easier ones. You can miss up to four equations in a run, so letting one difficult circle land to save two easy ones is a legitimate strategy.
Research on children trained in mental abacus found that experienced users hold numbers as a visual image of the beads, which makes their calculation relatively insensitive to verbal distraction. Shuzan in MyRin does not teach the abacus itself, but it trains the same fast, visual number fluency under time pressure.