This game is similar to Killer Sudoku. You need to fill in numbers from 1 to 9 into the boxes. When you fill in the numbers, they must not repeat on the same row or column, and that the numbers in a red group must calculate to the number shown on the group. The type of calculation used is shown on the number in the group. Note that unlike Killer Sudoku, the numbers in the red group can repeat. Use logic and calculation to deduct the numbers to be filled in. If you are stuck, press the hint button to review a correct number. But every time you use a hint, scores will be deducted. Moreover, if you solve the puzzle faster, your score will be higher.