MyRin Math Games Compared: Which of the Six to Play

MyRin has six games that are built on numbers. Some are calm puzzles you can think about for as long as you like. Others put you under a clock or drop new problems on you before you have finished the last one. They all involve arithmetic, but they train quite different things.

Here is how they compare, and how to use them together.

At a glance

• Sangaku: one equation with a blank, several answer choices. Calm accuracy.
• Balance Scale: add up one side, pick the weight that balances it. Addition and estimation.
• Sequence: find the rule behind a series of numbers. Pattern spotting.
• Arithmetic Blitz: as many sums as possible before the clock runs out. Speed.
• Shuzan: equations fall from the top and several can be live at once. Speed under load.
• Kakuro: a crossword of sums. Deduction with numbers.

Sangaku: equations without pressure

Named after the geometry tablets hung in Edo-period shrines and temples, Sangaku shows an equation with one or more blanks and asks you to choose the value that completes it. Higher levels bring multiple blanks and multi-step operations.

Its strength is that it lets you think. That makes it the best place to practise strategies until they feel natural: rounding and adjusting, rephrasing a subtraction as an addition ("12 minus what equals 7" becomes "7 plus what equals 12"), and eliminating answer choices that are the wrong size before doing exact arithmetic.

See the Sangaku guide for more.

Balance Scale: addition you can see

Balance Scale shows weights on one pan and asks you to choose the weight that levels the beam. The scale tilts as you go, so you get visual feedback as well as a right or wrong answer.

It is mostly addition, which makes it a gentle start for anyone who feels rusty. As levels progress, the totals get larger and the answer choices get closer together, so estimation becomes less useful and exact sums matter more. Our Balance Scale guide covers the trickier levels.

Sequence: find the rule

Sequence shows a series of numbers with one missing and asks you to identify the pattern. It is less about calculation and more about noticing structure.

A reliable method:

• Work out the differences between neighbouring terms. If they are constant, you are done.
• If not, look at the differences between the differences. A constant second difference points to square numbers or something like them.
• Try ratios. If each term is the previous one times the same number, the sequence is geometric.
• Check whether two separate patterns alternate in the odd and even positions.

The Sequence guide has worked examples.

Arithmetic Blitz: speed against the clock

Arithmetic Blitz (Anzan in the app, the Japanese word for mental calculation) shows an equation and four answer choices against a countdown. Each correct answer adds a little time. Each wrong answer takes some away.

That scoring rule matters. Guessing is expensive, so the game rewards being quick and right. The best players do not compute everything exactly. They estimate, use the answer choices to narrow things down, and then confirm with a small calculation. If the choices are 72, 75, 78 and 81 and your estimate is "about 75", you only need to check one digit.

Our article on mental math tricks covers the shortcuts that help most here. The Arithmetic Blitz guide has game-specific advice.

Shuzan: several problems at once

Shuzan, named after calculation with the soroban abacus, drops equations from the top of the screen. You resolve each one by tapping its answer before it reaches the bottom. On easy, one circle falls at a time. On medium, two fall together. On hard, four arrive in staggered waves. Miss more than four and the level ends.

That makes Shuzan the most demanding of the six. It is no longer just about calculating quickly. You have to decide which problem to deal with first, keep an eye on the others while you compute, and avoid panicking when several arrive together.

• Deal with the lowest circle first. It is closest to escaping.
• Glance at the next one while you tap. Reading the next problem while finishing the current one saves a surprising amount of time.
• Do not chase a hard problem. If one sum is slow, solve the easy ones around it rather than letting three escape while you work on one.

See the Shuzan guide for more.

Kakuro: logic with numbers

Kakuro is the odd one out. The arithmetic is small: sums of digits from 1 to 9. But the challenge is deduction. Each white cell belongs to an across run and a down run, each run has a target sum, and no digit can repeat within a run.

The key insight is that some runs have only one possible combination. Two cells that sum to 3 must be 1 and 2. Two cells that sum to 17 must be 8 and 9. Three cells that sum to 6 must be 1, 2 and 3. Start from those, and the rest of the grid opens up.

Kakuro is closer to sudoku than to the other math games. Our Kakuro guide and our comparison of kakuro and sudoku go further.

Which one to play

• Rebuilding confidence with numbers: Balance Scale and Sangaku.
• Getting faster at everyday arithmetic: Arithmetic Blitz, every day, for a few minutes.
• A real challenge under pressure: Shuzan on medium or hard.
• Enjoying numbers as puzzles: Sequence and Kakuro.

A simple progression

If you want to build mental arithmetic skill steadily, play the games in order of pressure:

1. Sangaku to practise strategies without a clock.
2. Arithmetic Blitz to apply them quickly.
3. Shuzan to apply them while juggling several problems.

When Shuzan starts to feel stressful, step back to Arithmetic Blitz for a few days. When Blitz feels easy, move up. Mix in Sequence or Kakuro on days when you want to think rather than race.

Four of the six have free demos you can try in your browser: Sangaku, Arithmetic Blitz, Balance Scale and Sequence.