A PUZZLE TO DEDUCE

Number Loom

A number-placement puzzle with one checked solution. Fill a 4 by 4, 6 by 6 or 9 by 9 board while respecting its rows, columns and outlined boxes.

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Your counters describe this puzzle only. Take as much time as you like.

THE ESSENTIALS

How to play

Each row, column and outlined box must contain every allowed number exactly once. Fixed clues cannot be changed.
Standard uses numbers 1–4 and 2 by 2 boxes. Hard uses 1–6 and 2 by 3 boxes. Expert uses 1–9 and 3 by 3 boxes.
Duplicate conflicts are marked. An entry without a current duplicate is not necessarily the final answer.
The puzzle finishes when the board is full, agrees with all fixed clues, and satisfies every row, column and box.

Select an empty square, then choose a number from the keypad or type it. Clear, Backspace, Delete or 0 removes an editable number.
Arrow keys move selection between squares; Tab and Shift+Tab also reach every control.
Undo restores the previous entry. Restart restores the same clues. New puzzle changes the arrangement; changing difficulty starts a fresh board.

Every starting pattern is checked for exactly one solution. Digit and row/column rearrangements preserve that property.

The difficulty choices change the board size and clue layout. They are not a measured human-solving rating.

There is no automatic solution reveal. Use a small candidate list to explain a number before committing to it.

TRY A DIFFERENT APPROACH

Number Loom · 3 MIN READ

Use a row with two gaps to separate a forced entry from a plausible guess, then bring the box constraints into the same reasoning.