The Power of ‘Candidate Numbers’ Revealed!

When you hit a roadblock in a Sudoku grid and find it hard to identify straightforward answers, then it is time to use candidate numbers. The candidate numbers help in filling out all the possibilities for each empty cell depending on the figures already present on the Sudoku grid.

If you’re solving Sudoku on paper, consider making notes with a pencil so you can easily erase them later. Alternatively, you could use a pen with very light pressure. Another option is to jot down small numbers in the corners of the cells to keep them unobtrusive for future reference.

When you are solving Sudoku on our website, you can utilize a special note feature by activating the ‘Pencil’ mode. It is necessary to accurately fill out candidate numbers because any mistakes can greatly increase the difficulty of solving the puzzle and consume more time. By systematically writing down possible values in the empty cells using figures that are not there yet, a better view of what can be done will emerge.

Image 1 is a Sudoku puzzle you are going to solve. Now focus on the 3×3 box highlighted with the purple frame as shown in image 2. Turn the ‘Pencil’ mode ON. Now write candidate or possible numbers in all the empty cells.

Once finished you can see that the numbers 5 and 7 are the possible numbers for the red frame. Since 7 appears once in the entire 3×3 box, it is the clear winner for the red frame. Also, numbers 5 and 6 are the possible numbers for the green frame and 6 is the clear winner since it appears once in the 3×3 box.

Incorporating candidate numbers as part of your strategy helps you identify where each digit should go besides allowing you to apply advanced methods of solving Sudoku riddles. These techniques largely depend on information that comes from candidate numbers thus simplifying one’s way through the puzzle.

On top of that, employing candidate numbers develops your analytical skills and improves how well you solve even those difficult puzzles that seem impossible initially. For more strategies and lessons about solving Sudoku see the Tips section on our website on which you can deepen your knowledge and enhance your skills.