A classic pastime where_ the objective is to fill in all the boxes with the numbers 1 to 9 without repeating any of them in the same row, column or box.
How do you play? Click on one of the blank boxes to bring up the nine numbers you can put in the hole and click on the number you think you can put there. If it turns blue it means it is a possible option and if it turns red it means that number does not go there.