CORRECT SUDOKU EXAMPLE FOR FREE

CORRECT SUDOKU EXAMPLE FOR FREE

Sudoku allows squares to be solved in different ways using different strategies.Īt the incredible value of just $9 SudokuDragon offers forever usage (no subscription, no adverts), download for free trial here. Note: Whenever there are eight allocated in a group with only one remaining empty you can assign a symbol by applying either the 'only choice', 'single possibility' or 'only square' rules as all of them come down to the same thing. It doesn't matter which rule you use, as long as the square is solved. You will often find that the same square can be solved by the ‘ single possibility’ rule as well as the ‘ only square’ rule.

But you can see that there is already a 3 in row I (square If) so a 3 cannot go in square Ic, the 3 must go in the other square Ac it is the only square in column c where a 3 can be allocated. In this puzzle column c (highlighted) has seven numbers allocated. This is different to the 'single possibility' rule where we looked at individual squares rather than groups. You are left with an only square within a group for a number to go in. For example if a group has seven squares allocated with only two numbers left to allocate it is quite common that an intersecting (or shared) group forces a number to go in one of the squares and not the other one. Often you will find that within a group there is only one remaining place that can take a particular number. To use this technique you choose a promising square and mentally run through each number in turn that might go in it, if you are left with only one number then that number must go in the square.įor a further in-depth guide click here Only square Sudoku rule The single possibility rule can be used to solve all the puzzle squares highlighted in green, so that makes it a very useful technique to have up your sleeve. But in row D there is already a 6 and 9 so that leaves 7 as the single possibility for square Da. Look at the purple square Da and run through possibilities: 1 2 3 4 5 and 8 that are allocated in column a leaves only 6 7 and 9 as possibilities. In this partially solved Sudoku there are quite a few readily solvable squares. So there is only one possibility for that square, and the number must go there. Because groups intersect you often find groups with more than one unallocated square but only one genuine possibility exists for one of the squares. Note: If there are eight squares solved in the group then this is just the same as the only choice rule. When you look at individual squares you often find that there is only a single possibility remaining.

Correct sudoku example