The more difficult Sudoku puzzles can’t be solved just by using the scanning techniques of crosshatching and counting. In these more complicated puzzles, scanning will still leave you with cells where you don’t know which of two or more numbers to choose.

Scanning techniques involve running your eyes over a row, column or region.

Cross-hatching is the scanning of rows and columns to identify which cell or cells in a region might contain a specific number.

Check out the mini Sudoku on the right.

Each row, column, and region of four cells must contain the numbers 1 to 4.

Sudoku puzzles come in different formats:

• digital Sudoku, whether on handheld devices, or online
• Sudoku printed or written on paper
• Sudoku games made out of plastic, wood, or similar

If you’re working on paper, be sure to use a pencil, not a pen, and have an eraser handy. You’re bound to make the occasional mistake, which you’ll want to erase.

Sudoku is one of the most addictive number puzzles to hit the world. Millions of people from all walks of like have caught up with the Sudoku puzzle in every form and version that exists today. People can solve a Sudoku by themselves, or play against another person in a timed game.

So you have to ask… what is this Sudoku puzzle anyway?

The most simple scanning technique is counting - select a row, column or region, and count the numbers in the cells in from 1 to 9, to identify the missing numbers.

Of course, this is most helpful when there is only one number missing from the row, column or region that you’re counting - then you know that number belongs in the missing blank cell.