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Last Free Cell

Last Free CellSTEP 0/3

Finding the last free cell

Learn the simplest strategy: Last Free Cell. You use it in situations where there is only one element missing in a given area:

Only one digit is missing in a full row or column
There is only one free space left in the 3x3 block

In such places you don't have to guess anything - the result follows directly from elimination.

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Last Free CellSTEP 1/3

Finding the last free cell in a row

Let's focus on the first row:

Horizontally we have: 1, 2, 3, 4, 5, 6, 7, 8
The missing digit is: 9

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Last Free CellSTEP 2/3

Finding the last free cell in a column

Now let's focus on the column:

Vertically we have: 2, 8, 4, 1, 5, 6, 7, 9
Let's sort them from smallest to largest: 1, 2, 4, 5, 6, 7, 8, 9
The missing digit is: 3

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Last Free CellSTEP 3/3

Finding the last free cell in a block

We still have to find the last free cell in the block:

In the block we have: 2, 4, 5, 6, 3, 8, 9, 1
Let's sort them from smallest to largest: 1, 2, 3, 4, 5, 6, 8, 9
The missing digit is: 7

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