Unveiling 'World's Hardest Sudoku Book Vol. 2': 200 New Puzzles to Challenge Enthusiasts, Continuing the Bestselling Legacy. It has been a long journey, but I am confident that these puzzles will ...

Did you consider yourself a mathematician the last time you sat down to solve a Sudoku puzzle? It’s certainly a mentally ...

Can you crack Killer Sudoku's mathematical twist? The objective of Sudoku is to fill each row, column and sub-grid with exactly one of each number from 1-9. In Killer Sudoku, the digits in each inner ...

The rules of Sudoku dictate that every row, column and 3×3 bolded box in the completed grid must contain the digits 1 through 9 exactly once. A surprising fact emerges from these simple rules. In ...

Click here to access the print version. Normal Sudoku rules apply, except the numbers in the cells contained within grey lines add up to the figures in the corner. No number can be repeated within ...