7
There is no math involved. Nothing has to add up to anything. You solve the puzzle with logic and
reasoning.
For example, look at the top-middle “box” of the puzzle shown on the right – the one with 5 and 9. It does
not have a 3. The following is one possible way to determine where to put 3 in the top-middle box.
The top-right box has a 3. The 3 is not just the 3 for the top-right box, but also the 3 for the whole top row.
The top-left box has a 3 as well. The 3 is not just the 3 for the top-left box, but also the 3 for the whole 2
nd
row.
So the 3 for the top-middle box cannot go in the top row or the middle row of that box. The 3 can only go in
the bottom row. But there are two empty cells in the top-middle box’s bottom row.
To determine, 3 goes in which one of these two cells, look at the box in the center (with 1, 3, 4 & 5). It has
a 3 which is not just for the box in the center but also for the 4
th
column.
Since there is already a 3 in the 4
th
column, therefore there is only one place a 3 can go in the top-middle
box, which is the lower right cell i.e. intersection of 3
rd
row and 6
th
column, so enter 3 in that cell.
This kind of logical-thinking will lead you to filling-in all the empty cells and solving the puzzle. Each puzzle
in most cases has just one solution.
