# Killer Sudoku 2 - Second Game

So how do you begin to fill a Sudoku puzzle that does not have a single number ion it? Killer Sudoku 2 lives up to its name. Sudoku is a game where you have to fill in the number 1 to 9 into a 3X3 grid and the numbers must never repeat. The grids come together to form a 9X9 grid and the columns and rows of the larger grid must have the same numbers 1 to 9 and they too must never repeat. This is a simple rule for most Sudoku players. In this game, there are other regions that have been added, and they do not have any uniform configuration. Some of them cover a single box, others cover two boxes, three boxes etc. Each of these boxes has a number attached to it. The numbers that you fill in that region have to add up to the number that is shown in the box. So now you can go back to the initial question about solving a puzzle that does not have a single number. The answer is simple; the boxes that cover a single square are the actual numbers. A single box with the number 9 can only be filled by the number 9. Now that you know that, you can go ahead and fill the rest of the game. This is a free online Sudoku game that will boggle most people if they do not grasp that simple and glaring hint; however a seasoned player will get it right away. The game has a hint button and the cost of using that button is a penalty of 100 seconds added to your time. There is no point in using this button especially given that when you start eliminating candidates, the math in filling this puzzle will be apparent. Go ahead and have some mathematical fun.