KEY POINTS:
Fill the grid so that every column, every row and every 3x3 box contains the digits 1 to 9.
Tip - If you would like to print out the Sudoku puzzle, right-click on the Sudoku image and from the pop-up menu that then appears - choose the command "Print Picture...".
This will create a larger printed version which is easier to read compared to using the Print command from the File menu in your browser.