Pointing
MediumWhen, inside a box, every place left for a digit lies in the same row (or column), the digit of that box is on that line. So no other cell of that line, outside the box, can hold it.
How to spot it
- With notes, look at where a digit can go inside a box.
- If those cells line up in one row or one column, the digit is there.
- Remove it from the rest of that row or column.
Why it works
The box needs the digit once, and its only places are on one row. So that row gets its digit from this box, and nowhere else.
Example
9
1
5
7
9
4
5
3
9
2
6
7
9
5
3
8
4
3
5
9
1
9
8
2
3
7
5
5
2
9
6
9
6
7
6
5
2
7
8
9
Look at the 4s in box 9.
Common mistakes
- Removing the digit from the box itself instead of from the rest of the row.
- Calling it pointing when one of the places is off the row.