SUDOKU

Fill the grid so every row, column and box holds 1 to 9 once. Three boards a day — Easy, Medium and Hard — and none ever needs a guess.

• Tap a cell, then a digit. The right digit locks in. A digit already in the row, column or box is refused, free — the clash is ringed.
• A digit the board allows but the puzzle does not is a mistake: it shows red, costs 8, and its key is struck for that cell.
• Notes pencils candidates into a cell — never checked, never charged. Erase clears a wrong digit or a cell’s notes.
• Hint fills the next cell a solver would and says why, for 4. It asks twice.
• The first board you finish is today’s score: 100, less 8 a mistake and 4 a hint, never under 10 — though a board filled entirely by hints scores 0. The other two boards stay open, for fun.

One score a day. Your scores are kept — Statistics is in the menu — and Sudoku sits outside the daily line-up, so it never moves your day’s total.

Read the full guide, with strategy