# Prime Number Puzzle: Sokyo — Chain-Reaction Math Brain Game

> Chain-Reaction Math Brain Game (iPhone/iPad app by TOMONOBU HASUMI.)

- Source: https://appshunter.io/ios/app/prime-number-puzzle-sokyo/id6789144447 (this page in markdown: same URL + `.md`)
- Developer: [TOMONOBU HASUMI](https://appshunter.io/developer/1734539436)
- Category: Games, Puzzle
- Price: $1.99
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English, Japanese
- Released: 2026-07-12
- Data updated: 2026-08-15
- User reviews in markdown: https://appshunter.io/ios/app/prime-number-puzzle-sokyo/id6789144447/reviews.md

## What is Prime Number Puzzle?

Tap a red number. Pop! It splits, chains, and the board clears away — and honestly, it's kind of addictive.

Sokyo is a chain puzzle where you tap primes to clear the board.
Play a few rounds and you'll get friendly with numbers without even trying.
"What divides this?" "2×3 makes 6" — you pick up multiplication and division without it ever feeling like homework. Even if numbers aren't your thing, you'll just be playing a game.

■ Easy to learn
Tap a red tile (a prime) and every number it divides in its row and column splits at once. If a split makes a new prime, that one fires too — a chain! The deeper you chain, the more clears at once and the bigger your score.

New numbers keep coming every turn. Think a step ahead and see how long you can last before the board fills up. A perfect little brain workout for a spare minute.

■ Great for
- A quick mental break
- Anyone who loves numbers or puzzles
- Getting comfortable with numbers through play (kids too)

■ Features
- Simple rules, surprising depth
- Gets tougher as you go
- Light & Dark
- No ads, no in-app purchases, no data collected
- Don't know primes? You'll pick them up as you play

Tap, chain, and clear them all.


## Version history (last 3 releases)

### 1.2 — 2026-08-12

We improved the App Store listing to make the app easier to find.

### 1.1 — 2026-07-14

Performance improvements and minor fixes.

### 1.0 — 2026-07-12

No release notes.

## More apps by TOMONOBU HASUMI

- [ChibiCopy - Clipboard Manager](https://appshunter.io/ios/app/chibicopy-clipboard-manager/id6747174509)
- [もじポン](https://appshunter.io/ios/app/id6785442240)

All apps by TOMONOBU HASUMI: https://appshunter.io/developer/1734539436

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-15.*