Nurikabe
Separate numbered islands with a connected sea.
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How to play
An island is an orthogonally connected white region containing one number and exactly that many cells. All black cells connect; no black 2×2 block is allowed. Numbered cells stay white.
Use the feedback
Attempt an answer before looking at a hint or explanation. If it differs from the expected answer, compare the reasoning one step at a time. For a number problem, substitute your result back into the question. For a passage, point to the words that support your interpretation.
About this activity
These compact puzzles are practice activities, with a deliberately small board or sequence. They are not a complete catalogue of tournament puzzles. There is no timer or competitive ranking. Correct-answer counts describe this task only.
Some puzzles can have more than one valid solution; grid checks accept any solution that meets the displayed constraints. Hints follow a known example solution. Familiarity, hints and previous attempts affect performance.
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Original examples and code created with AI assistance. No IQ, diagnostic or therapeutic interpretation is provided.