We are going to work up to Sudoku by starting with a 4 X 4 square like so:
We'll start with symbols. Notice that in this 4 x 4 square there are four 2 x 2 squares. Each row across, each column down and each 2 x 2 square has each of the four symbols only once. A Sudoku puzzle is solved when you fill in all the spaces following the rules. Print out the following three puzzles and see if you can fill them in by following the rules:
1. Each row has one of each symbol.
2. Each column has one of each symbol.
3. Each 2 x 2 square has one of each symbol.
When you finish this, go on to 6 x 6.