Every row, column and box uses each number once. Start with 4×4, then move up to 6×6. Solve on screen or print, with the answer key on page 2.
Fill every empty square so each row, each column and each outlined box contains every number exactly once. Every puzzle here is checked by computer to have exactly one solution.
Love number puzzles? There is a whole new kind waiting in the app. Free to start.
Get it free on the App Store