This is an example of a 16x16 Sudoku. They are very similar to standard 9x9 Sudoku puzzles, but instead of using the number 1-9, we use the numbers 1-9, and also the letters A, B, C, D, E, F, and G. Each row, column, and 4x4 region must be contain one and only one of these.

You can use all of the same techniques that you would use on a standard 9x9 Sudoku, but it is a bigger puzzle, and will take you longer!

Have a look at the highlighted square. That 4x4 region already contains 1, 2, 4, 5, 7, 9, D, E and F. The column already contains 2, 4, 5, 7, 8, 9, B, C, D and F. The row already contains 2, 3, 4, 6, 8, 9, A, B, C, D, E, F. Combining all of those together leaves us with just the letter 'G' that hasn't already been taken.

The highlighted cell must be a G!

Look at the three highlighted cells in this puzzle, you can work out directly what they all are without needing to fill in any more of the puzzle.

Have a try now!