How to play Sudoku

By clicking on any of the blank squares you will be able to enter the number you require for that square. You may change any of the numbers you have entered at any time until you hit the 'Finish' tab.

By clicking on the Scratchpad button you will be able to bring up a small editable area near the top of each square in which you can keep a note of the possible alternatives for that square.

The 'Hint' button can give you assistance in completing the puzzle but will cost you points. In order to benefit from a hint, click on the square for which you want a hint and then hit the 'Hint' button. This will reveal the number in that square.

How do we score it

For completing the puzzle correctly you will score 90 points. For every hint you use before submission and for every erroneous number in your submitted entry, nine points (10% of total) will be deducted.

Time bonus: For completing the puzzle within the target time of ten minutes you will score a further 90 points. For each minute or part of a minute in excess of that target time three points will be de-ducted. If you fail to score any points for completion you will also not qualify for time bonus points, no matter how quickly you submit your entry.