Now try to use the same technique but now with an almost filled-in row or column - find the one where only one number missing (then the answer is obvious) or two ones missing - try both options and figure out the right one. Which one is correct? Just place 3 and look across the whole row, then the column: is there a duplicate? Try the same with 7 and you'll get the correct option. For example, if a 3x3 square lacks just the numbers 3 and 7, we have only two options on how to place these two remaining numbers - 3 in a first cell and 7 in a second one or vice versa. You will certainly see a square where just one or two numbers are missing. Start a Sudoku puzzle on an Easy level to learn all the techniques quickly. Sounds like a tricky task? Just start scanning the board and you'll find all clues you need, one by one, and get the puzzle solved.
So each number from 1 to 9 occurs only one time in each row, column and region. Now you just need to fill the remaining cells with numbers from 1 to 9, obeying the only rule:Įach row, column or region must not contain repetitive numbers. The more cells are pre-filled the easier the puzzle.
You start a Sudoku puzzle with some cells already filled in with numbers. So each row, column or region contains nine cells. In each Sudoku puzzle you have a 9x9 grid, divided into nine 3x3 square regions (you can just look above to get an impression).
