How to Win at Sudoku

Sudoku is a Japanese number game that has hit the rest of the world like a storm. Suddenly sudoku puzzles can be found everywhere--books, magazines and daily newspapers. You can even locate sudoku on the Internet. Like other types of puzzles, sudoku can range from easy to challenging. Follow these steps to win at sudoku.

Difficulty: Moderate

Instructions

1. Understand the rules of sudoku puzzles. Complete each row, column and block with letters from 1 to 9. No number can be repeated. The key to winning at sudoku is to constantly look at the puzzle in different ways.

2. Locate any easy to fill in squares. Check the numbers already filled in each column of 3x3 blocks. If you find a 4 in the last column of the first box and in the first column of the last box, then you know the remaining 4 must be in the middle column of the middle square block. If two of those squares are already filled with numbers, then the 4 goes in the remaining squares.

3. Do this search on the other two remaining blocks of columns. Then do it with each block of rows. You should be able to fill in a few numbers this way.

4. Check every number you filled in and see if it offers you more possibilities to discover which number goes in which square. Filling in numbers often causes a chain reaction of number discoveries.

5. Look for single rows, columns or 3 by 3 blocks with only 2 or 3 blank squares. Look at what numbers are possible in the remaining squares. Don't forget to check the row, column and block for clues. Eliminate numbers you already used.

6. Repeat Step 4. This step should also be repeated any time you get stuck with your sudoku puzzle.

7. Pencil in the remaining numbers that could go in a single square. Do this for an entire row, column or 3x3 block. If your block has only one place that an 8 could go, write it in, then eliminate 8 as a choice anywhere else in that row or column. At this point, you're finding numbers by eliminating the possibilities.