Sudoku is a puzzle in which players need to insert the numbers into a grid consisting of squares that are then divided in to further squares. Numbers should be placed in the squares so that every number appears once in a horizontal line, vertical line and in a square.
I have attached three different levels.
Easy: You are only allowed to use the numbers 1,2,3,4
Medium: Use the numbers 1-9 only
Hard: Use the number 1-9 only
This puzzle requires lots of resilience and you are often going to need to change your answers. Using a pencil will help you draft in your answers.