First, you have to decide which of the three levels you want to play. Then you have to choose whether to play Sowdoku online or print it out.

If you decide on the online game, you see all the numbers you need to solve the puzzle to the right of the grid. Click on the numbers with your mouse and drag them over to the square where you want them to go. If you are not sure, you can click on "Check” and see if everything is right so far. Red rows and columns show you the wrong numbers.

If you prefer solving Sowdoku on paper, click on "Print”. You can also print out the solution if you are at a loss how to go on.

How Sowdoku works:

You may know the number puzzle Sudoku. Sowdoku works on the same principle.

In case you have never played Sudoku, here’s a short explanation of the rules and the aim of the game.

The aim is to fill all the squares with the right numbers. As you can see in the picture above, Sowdoku consists of a grid with 3 x 3 boxes that are each divided into 3 x 3 squares. The altogether 81 squares are spread over nine rows and nine columns.

So that the puzzle can be solved, numbers are already provided in some of the squares. In each row, each column and each 3 x 3 box, each digit from 1 to 9 must only occur once. If you think carefully, you can complete the Sowdoku right down to the last number.

Have fun!