Shikaku (Rectangles)
Divide the grid into non-overlapping rectangles matching numbered area clues.
How to Play & Master Shikaku (Rectangles)
Complete official rules, deductive mechanics, and tournament-grade strategies.
Core Objective
Divide the grid into non-overlapping rectangles and squares so that each piece contains exactly one number equal to its cell area.
Official Step-by-Step Rules
- 1Every grid cell must belong to exactly one rectangle.
- 2Each rectangle must contain exactly one numbered clue cell.
- 3The number in the clue cell equals the total number of squares enclosed in that rectangle.
Pro Tips & Solving Techniques
- ★Prime numbers (like 2, 3, 5, 7) can only form 1×N rectangles in a straight line.
- ★Start with corners and edges where rectangle orientations are restricted.
Cognitive Neuroscience & Brain Benefits
How regular puzzle practice enhances neuroplasticity and mental acuity.
Playing Shikaku (Rectangles) activates multiple brain networks simultaneously—including the prefrontal cortex for working memory and deductive logic, and the parietal lobe for pattern recognition. Daily solving strengthens neural connectivity, reduces stress through focused mindfulness, and builds fast problem-solving fluency.
Frequently Asked Questions
Everything you need to know about playing Shikaku (Rectangles) online.
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