Steps 4-6
| Step 4 | ||
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Single Possibility There highlighted 3x3 square has only one empty tile. The missing number is 2, therefore it must be a two. |
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| Step 5 | ||
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Simple Elimination The highlighted column is does not yet have a 9. All but one of the cells can be eliminated by the 9's in crossing rows and the top 3x3 square. The remaining tile is assigned as 9. |
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| Step 6 | ||
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Simple Elimination There are three empty tiles in the highlighted 3x3 square. The missing numbers are 2, 3 and 5. The crossing row eliminates two of them from being 3, so 3 is assigned to the only remaining tile. |
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