Lesson 5 · Beginner technique

Naked Singles

Solve a cell when its candidate list has been reduced to one number.

Written and puzzle-tested by Chamara S. Kodikara · Last reviewed 3 August 2026

See the logic move

Use Next to reveal each reason. On the final step, tap the highlighted cell to complete the move yourself.

Live logical proof · Naked Single

Step 1 of 3

Focus

row 5, column 5 has only one legal candidate: 5.

What the board is showing

TargetThe cell currently being tested.R5C5
Relevant unitThe row, column, or box controlling this move.Row 5, column 5, and its 3x3 box

Explain it simply

A Naked Single is not hiding: its cell openly shows just one possible candidate.

Step by step

  1. Choose an empty cell.
  2. Check its row, column, and box.
  3. Cross out blocked candidates.
  4. Place the only candidate left.
Quick check: If a cell has candidates 3 and 8, is it a Naked Single?

No. A Naked Single has exactly one candidate.

Turn logic into skill

Practice this technique on a live board

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