Challenge Yourself

After finishing any puzzle, go back and find every naked pair and hidden single you used. Catalog your techniques.

Challenge Yourself
✓ Completed! 👍
2
6
3
9
8
5
1
1
9
5
7
2
3
4
7
2
9
6
4
5
3
6
8
9
7
1
2
7
8
3
9
5
2
9
9
8
4
1
2
3
5
9
6
8
5
4
8
3
1
2
7
Pro Tip

Box-Line Reduction: if all candidates for a digit in a row or column are within one box, eliminate that digit from the rest of the box.

Pro Tip