SUDOKU

How to play Sudoku

Fill the 9×9 grid so every row, every column, and every 3×3 box contains each digit 1–9 exactly once. Tap a cell to select it, then tap a digit on the keypad — or use a number key. NOTES mode lets you pencil in candidates without committing.

Solving techniques

Start with rows, columns, or boxes that already have many digits — they constrain the rest. Look for "naked singles" (cells with only one possible value) and "hidden singles" (boxes where a digit can only legally go in one place). Pencil-mark candidates and eliminate them as you commit digits.