Fill in a number in every square so that every number appears exactly once in each row, each column and each block marked by thick lines.
To place a number, click in a square to select it, then type the number on the keyboard. To erase a number, click to select a square and then press Backspace.
Right-click in a square and then type a number to add or remove the number as a pencil mark, indicating numbers that you think might go in that square.
When you master the basic game, try Jigsaw mode (irregularly shaped blocks), X mode (the two main diagonals of the grid must also contain every number once), Killer mode (instead of single-cell clues you are given regions of the grid each of which must add up to a given total, again without reusing any digits), or all of those at once!
Courtesy of Simon Tatham's Puzzle Collection via the MIT license.
We hope that the free math worksheets have been helpful. We encourage parents and teachers to adjust the worksheets according to the needs of the child. For more difficult questions, the child may be encouraged to work out the problem on a piece of paper before entering the solution. We hope that the kids will also love the fun stuff and puzzles.
We welcome your feedback, suggestions, comments and questions about this site; please submit your feedback via our Feedback page.