Sudoku Hints II

Sudoku Hints For Slightly Harder Puzzles

Look for the only possible choice.

In the example at the left, I have identified the only possible positions for the number 7.

The existing sevens prevent the number 7 from being in any other empty cells except for the ones circled in red.

Sometimes you will encounter the situation where there is only one place a number can possibly go. This is a classic example.

At first glance one might think that it isn't possible to place a 7 in the top three regions. After all each region has two places a 7 can go.

Upon closer scrutiny, you will see that cell (R2,C5) is the only place a 7 can go in row 2 even though there are other empty cells in that row.

This is just another way to find a cell's solution using a little logic.

Hints To Solve Solve Sudoku With Two Cells Missing.






Here are two Sudoku hints that will help you solve a row or column where two cells are empty.

Look at the graphic at the left. You will notice that in column 1 we are missing two numbers. They are circled in red.

Counting from 1 to 9 you find that a 2 and a 4 are missing. But where do they go? To solve this column, look at row 8.

You will notice that there is a 4 in (R8,C5). Since there can only be one 4 in row 8, the cell (R8,C1) must be a 2. Therefore the other empty cell (R2,C1) must be a 4.

Simple, eh?

Now let's look at row 5. Again you have two empty cells circled in red. Counting from 1 to 9 you will find that a 3 and a 4 are missing.

This time you don't have a 3 or a 4 in column 2 or column 7 to help you solve the two empty cells in row 5. So how can you solve it?

It's simple. If you look at the right - center region carefully, you will see that there is a 4 in cell (R6,C7). Since you cannot have two 4s in the same region, cell (R5,C8) must be a 3.

If cell (R5,C8) is a 3, cell (R5,C2) must be a 4. There you have done it! You learned two new Sudoku hints that will help you solve two missing cells in a row or column.

More Sudoku Hints






Sometimes you will be in a situation where this Sudoku hint will work.

If you look at the graphic at the left, let's try to find a 3 in the middle stack of three grids.

I have circled in red the only possible positions a 3 can go in the middle stack. Check it out using the scanning method.

When you look at column five you will notice that a 3 must go in that column in the middle region. There is no other place available in the middle region.

Since a 3 must go in column 5 in the middle region, it can not go in cells (R8,C5) or (R9,C5) of column 5. Therefore you can conclude that the only possible place a 3 can go is in cell (R8,C4) in the lower middle region.

You probably won't use this hint often, but it is a nice one to add to your Sudoku solving tool chest.