To play Sudoku is to fill every column, row and 3x3 box with
numbers 1 to 9. The game does not use any math operation, you just need to
analyze every row, column and every 3x3 box and use elimination to determine
the appropriate cell for every number.
What do I mean in eliminating cell? Elimination is use to
determine where you can put the number. Eliminating rows or columns will helps you to locate the appropriate cell for each number. Example, if you’re looking
for appropriate cell where you can put number 2 in a column, you should look
for already given number 2 and eliminate the entire row of cell. Eliminating
the entire row will eliminate a cell in a column. If you came up with only one
cell not eliminated in a column, you can already put number 2 in that cell. The
process is used vise versa.
You can also eliminate cells in a row or column by analyzing
the 3x3 box. Each 3x3 box should have numbers 1-9; it means no repetition of
number in a 3x3 box since you only have 9 cells to put number 1-9 and it only
means that if number 2 is already existing in the 3x3 box, all 3 rows and 3 columns in a 3x3 box should be eliminated when looking for appropriate cell to put number 2.