Sudoku

Fill the grid with digits 1–9 without repeating in any row, column or box.

1. Fill the 9 × 9 grid so that every row, every column and every 3 × 3 box contains the numbers 1 to 9, with no repeats.
2. Tap an empty cell and pick a number from the pad below; tapping the same number again clears it. On a keyboard, move with the arrow keys, type 1 to 9, and erase with Backspace, Delete or 0.
3. Choose Easy, Medium or Hard: higher levels give you fewer starting numbers, and switching level starts a new sudoku. Every puzzle has exactly one solution, and the bold starting numbers can't be changed.
4. A number that repeats in its row, column or box turns red, but a number that isn't red isn't necessarily right. The small figure under each button on the pad shows how many of that number are still missing.
5. Selecting a cell shades its row, column and box and highlights every matching number. Use it to spot the one cell in a box where a given number can go.