Solution Method A

Solution Method A is aimed at solving the sudoku empty cells and has 4 variants.

Basic rule:
The basic rule for solving a sudoku puzzle is that the numbers 1 to 9, only once per row and one column per AND once a block may prevention. An empty cell can therefore have a maximum of nine options.
These options will be less as the puzzle progresses (if for example a two in a row is completed, then for all cells in this row option two removed).

Solution Method A1 ("Singles")

This method is a solution for all 81 cells along.
If a cell is found where still a bad option for overtime, then this option will be the value that must be completed.

For example:
The following puzzle cell E5 has only 8 on the option. The other options 1,2,3,4,5,6,7 and 9 were previously left out "because these songs had already been introduced in the same row (options 1,3,7,9), the same column (option 2,4,5,6) or the same block (option 2).
This will in cell E5 the number 8 must be completed.

Solution Method A2 ("Hidden Singles in a row")

Look row for row or there is an option only once in this row appears.
If so, then the cell where this option prevents the solution.

For example:
The following puzzle has cell C6 as the only cell in the row 8 on the option.
The option 8 from all other cells in this row 'left out'.
This will in the C6 cell number 8 should be completed.

Solution Method A3 ("Hidden Singles in a column")

Watch column for column or there is an option only once in this column appears.
If so, then the cell where this option prevents the solution.

For example:
The following puzzle has cell A1 as the only cell in the column 8 on the option.
The option 8 from all other cells in this column 'left out'.
This will in cell A1 the number 8 must be completed.

Solution Method A4 ("Hidden Singles in a block")

Look at sudoku block or there is an option only once in this block appears.
If so, then the cell where this option prevents the solution.

For example:
The following puzzle has G4 cell alone in this cell block 1 on the option.
Option 1 is from all other cells in this block already 'left out'.
This will be the No. 1 cell G4 to be filled.