Every 5 touches one 1, one 2, one 3, and one 4 — up, down, left, right. Diagonals don't count, and 1-4 can each appear only once per row and column.
Given 5
Given number clue
Click to fill: 1 → 2 → 3 → 4 → blank
- Click a cell to cycle its value, or type
1–4(Backspaceto clear). - A 5 glows green when correct, red when wrong.
- A red outline means a repeated value in that row or column.
- Solved is detected automatically — no need to press Check.