How to Solve Sudoku Puzzles Easily
- 1). Observe the puzzle carefully. Examine the 81-box puzzle. Notice that the rows and columns are divided into nine separate 3-by-3 boxes -- some of which already include some correct numbers.
- 2). Fill in all obvious numbers first. If an entire Sudoku row or column leaves only one blank box, deduce which number is missing and write it in. For example, if the entire first row is filled with numbers 1, 2, 4, 5, 6, 7, 8 and 9 -- not necessarily in that order -- then 3 is the only number for that box. Write in all obvious numbers you can find -- numbers that have not already been filled in -- to reduce the number of empty boxes as you continue.
- 3). Find naked singles -- any box where only one number can fit because it is the only unused number. Draw tiny numbers in the corner of each box for all possible numbers that might fit. Continue this process across every row and column. Boxes often have as many as four possible numbers and as few as one. Fill in the naked single number as your answer.
- 4). Identify naked pairs. Notice any two possible numbers that are duplicated in boxes in the same column or row -- this would make a naked pair. Make sure these boxes contain only the same two numbers. If you find a naked pair, remove those two numbers as possible numbers in any other boxes in that row or column. Finding naked pairs often leads the player to safely assume that one of the two duplicated numbers goes in one -- and only one -- of those boxes.
- 5). Discover hidden pairs. Look at boxes in the same column or row with three or four possible numbers. Identify any boxes that duplicate two numbers. Scratch out the remaining numbers in the box if you find a hidden pair -- as the same rule usually applies to the naked pair identification tactic.
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