By clicking on the Scratch Pad button you will be able to change the selected square to keep a note of the possible alternatives for that square. Clicking Scratch Pad again will revert to any previous number entered without losing your notes.

The 'Reveal' 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 'Reveal' button. This will reveal the number in that square.

Scoring for Easy

The par target is to complete the puzzle within 10 minutes without making any errors or using any hints. If you can attain that target you will score 100 points.

Your score will be increased or decreased by 10 points for every minute or part minute above or below that par target. No points are awarded if you exceed a time of 20 minutes.

Your score will be reduced by 20% for every hint you use and every error you make. No points are awarded if you use five or more hints or make five or more errors.

Examples

• Puzzle completed without hints or errors in 7 mins 15 secs: Score 120
• Puzzle completed with 2 hints or errors in 7 mins 15 secs: Score 120 - 48 = 72
• Puzzle completed without hints or errors in 14 mins 45 secs: Score 50
• Puzzle completed with 3 hints or errors in 14 mins 45 secs: Score 50 - 30 = 20

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Scoring for Medium

The par target is to complete the puzzle within 15 minutes without making any errors or using any hints. If you can attain that target you will score 150 points.

Your score will be increased or decreased by 10 points for every minute or part minute above or below that par target. No points are awarded if you exceed a time of 30 minutes.

Your score will be reduced by 20% for every hint you use and every error you make. No points are awarded if you use five or more hints or make five or more errors.

Examples

• Puzzle completed without hints or errors in 11 mins 15 secs: Score 180
• Puzzle completed with 2 hints or errors in 11 mins 15 secs: Score 180 - 72 = 108
• Puzzle completed without hints or errors in 15 mins 45 secs: Score 140
• Puzzle completed with 3 hints or errors in 15 mins 45 secs: Score 140 - 84 = 56

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Scoring for Hard

The par target is to complete the puzzle within 20 minutes without making any errors or using any hints. If you can attain that target you will score 200 points.

Your score will be increased or decreased by 10 points for every minute or part minute above or below that par target. No points are awarded if you exceed a time of 40 minutes

Your score will be reduced by 20% for every hint you use and every error you make. No points are awarded if you use five or more hints or make five or more errors

Examples

• Puzzle completed without hints or errors in 13 mins 15 secs: Score 260
• Puzzle completed with 2 hints or errors in 13 mins 15 secs: Score 260 - 104 = 156
• Puzzle completed without hints or errors in 21 mins 45 secs: Score 180
• Puzzle completed with 3 hints or errors in 21 mins 45 secs: Score 180 - 108 = 72

Note that only your first score for each puzzle will be entered onto the leaderboard and that you must be registered and logged in.