Everything you need to know about rectangle partition puzzles: what they are, where they came from, how to solve them, and where to play.
A rectangle partition puzzle — also known as shikaku (四角に切れ), rectangular dissection, or divide-by-box — is a logic puzzle played on a grid. Some cells contain numbers. Your task: divide the entire grid into non-overlapping rectangles so that each rectangle contains exactly one number, and that number equals the rectangle's area.
It's a pure spatial reasoning puzzle. No arithmetic beyond counting cells. No guessing — every puzzle has a unique solution reachable through logical deduction.
Rectangle partition puzzles were popularized by Nikoli, the Japanese puzzle publisher famous for bringing Sudoku to the world. Nikoli publishes these puzzles under the name Shikaku ni kire (四角に切れ), meaning "cut into rectangles."
Like Sudoku, Kakuro, and other Nikoli puzzles, Shikaku follows a philosophy: simple rules, deep logic. The rules fit in one sentence, but the solving techniques range from trivial to fiendish.
| Puzzle | Type | Core Skill | Key Difference |
|---|---|---|---|
| Shikaku / MeowBlock | Rectangle partition | Spatial reasoning, area | Draw rectangles matching numbered areas |
| Akari / MeowTrail | Light-Up | Line-of-sight logic | Place bulbs, illuminate cells, block by walls |
| Sudoku | Number placement | Deduction, elimination | Fill digits 1-9 in rows/columns/boxes |
| Kakuro | Cross-sums | Arithmetic, combinations | Digits sum to given totals |
| Nonograms | Pixel art logic | Row/column counting | Fill cells to reveal a picture |
The standard form: rectangular grid, numbered cells, tile with rectangles. This is what MeowBlock implements.
Some variants use hexagonal or irregular grids instead of square cells. The core logic remains the same — partition into regions matching the numbers.
Nikoli sometimes combines Shikaku rules with other puzzle types. For example, a grid might have both Shikaku numbers and Akari-style black cells.
See our full strategy guide for detailed techniques. Here's a summary:
MeowBlock is a free online Shikaku game with cat visuals. See how it compares to the classic Nikoli Shikaku, or jump straight into a game.
| Platform | Name | Features |
|---|---|---|
| meow-block.com | MeowBlock | Free, cat-themed, unlimited procedural puzzles, daily challenge |
| Nikoli.com | Shikaku | Original publisher, handcrafted puzzles, subscription required |
| Various apps | Shikaku / Rectangle Puzzle | Mobile apps on iOS/Android, varying quality |
Yes. "Shikaku" (四角に切れ) is the Japanese name from Nikoli. "Rectangle partition" and "rectangular dissection" are English names for the same puzzle.
Yes! A square is a special case of a rectangle. A "4" can be a 2×2 square, a 1×4, or a 4×1 rectangle.
MeowBlock supports up to 7×7 (49 cells). Nikoli publishes Shikaku up to 30×30. The solving logic scales — larger grids just take longer.
Absolutely! Small grids (5×5) are excellent for developing spatial reasoning and area concepts. No reading required — just numbers and shapes.