Shikaku Strategy Guide

Key Strategies

1. 01

   Find isolated number cells first

   A numbered cell surrounded by walls or other rectangles has limited room. Determine its rectangle dimensions (factors of the number) and which orientation fits the space.

2. 02

   Rectangles must be axis-aligned

   Shikaku rectangles cannot be tilted. The number in each rectangle equals the rectangle's area (width × height). Always think in terms of factor pairs.

3. 03

   Use the grid edges as constraints

   Numbers near corners or edges have fewer rectangle orientations available. Solve boundary numbers early to limit options for interior numbers.

4. 04

   Eliminate impossible rectangles

   For each numbered cell, draw all valid rectangles (including all factor pairs). If any valid rectangle would overlap another number's only possible rectangle, eliminate it.