No 13, Year 13, May 2016
Page 43
This time a sudoku
How to play sudoku? The objective is to fill a 9x9 grid so that each column, each row, and each of the nine
3x3 boxes (also called blocks or regions) contains the digits from 1 to 9 (without being repeated). A cell is
the smallest block in the game. A row, column and region consists of 9 cells and the whole game consists of
81 cells.
The most basic strategy to find missing numbers is scanning and it consists of:
1)Cross-hatching.
2)Counting.
1) You scan rows and columns to eliminate where a specific number can be in
a given region. There is only one legal place for each number.
2) In counting you simply count all the different numbers that's in a row,column
and region that connects to one cell. if there is just one number missing then
that's what should be in the cell.
5
9
6 8
1
4
8 5
3
6 1
5
9
4
1
8
9
7
1
5
8
5
2
6
6
1
5
9
1
4
1,2,3,4,5,6,
7,8,9
4
9 1 5
2
6
5
7
9
8 6 4
3
2
4
9 3
6
7
6
7
5
2
3
8
6
9
7
3
4
1
2
3
3
8
5
4
6
6
9
1
5
6
2
8
HAVE FUN AND LEARN!
2
7
1
1
5
8