Transcript How To Solve Sudoku Puzzles

Examining the top three rows first
The number 5 appears in row one and row
three.
Row two requires a 5. It has to be
located in the middle 3x3 box.
Two possible locations for 5 in centre
box
The centre column
already has one 5 so it
cannot be above the 8.
Thus, it has to be above
the 9 on the second
row
Examining the top three rows first: 5
appears in row one and row three.
Row two requires a 5. It has to be
located in the middle 3x3 box.
Two possible locations for 5 in centre
box
The centre column
already has one 5 so it
cannot be above the 8.
Thus, it has to be above
the 9 on the second
row
Now scan down the three central columns:
Now scan down the three central columns:
The second and third columns already
have the number 5 - but the first column
also needs a 5.
A 5 has to be located in the lower 3x3 grid box
as the two above already have 5 in them.
The bottom row of nine boxes has a 5 already
so it cannot go in row 9.
Thus, 5 has to go just above the 2 on the
first row of the lower middle 3x3 grid box.
Now examine the central three
rows - row 4 to row 6.
The number 2 appears in rows
5 and 6 but not in row 4
Fill in the number 2 in row 4 of
the central 3x3 grid box.
But Column 4 has a 2 already
Thus, the 2 in row 4 has to go
above the 4 in the central box
Now examine the central three
rows - row 4 to row 6.
The number 2 appears in rows
5 and 6 but not in row 4
Fill in the number 2 in row 4 of
the central 3x3 grid box.
But Column 4 has a 2 already
Thus, the 2 in row 4 has to go
above the 4 in the central box
Continue scanning across and
down the columns and grids
filling in the ‘easy’ numbers.
It can help to systematically go
through the numbers 1 to 9 in
sequence for each horizontal and
vertical group of three sub-grids.