How To Solve a Killer Sudoku
The Killer Sudoku (also called Addoku) is like a Sudoku in that every row, column and 3 x 3 block must contain 1 – 9.
The difference is that no digits are filled in to start you off. The digits in the cells linked by a shaded line (a set) add up to a total, which is shown on the grid. Use these given totals to find the right digits for each set. No digit may appear twice in a set.