How To Solve Sudoku Puzzles

Sudoku is generally played on a grid of 9 x 9 squares. There are other variants of Sudoku with smaller and larger grids.

Each puzzle contains nine rows, columns, and boxes.

Example sudoku grid showing a row

Rows

Rows run horizontally across the grid. In a standard 9x9 sudoku puzzle grid, there are nine rows.

Example sudoku grid showing a column

Columns

Columns run vertically down the grid. In a standard 9x9 sudoku puzzle grid, there are nine columns.

Example sudoku grid showing a box or square

Boxes

Boxes, also known as squares, are 3x3 grid areas denoted by darker, bold lines. In a standard sudoku puzzle grid, there are nine boxes.

How to Play

A Sudoku puzzle will provide some numbers for you. 

To complete the puzzle, fill the empty squares with a missing number according to the following rules: 

Rules

  1. Each row, column, and box must contain all the numbers from 1 to 9.

  2. Each number from 1 to 9 can only be in each row, column, and box once (no repeats).

Once the puzzle is solved, each row, column, and box will contain every number from 1 to 9 only once, as seen in this example solution.

Picture of an unfinished sudoku puzzle

Puzzle

picture of a completed sudoku puzzle showing the solution.

Solution

Handy Tips To Get You Started!

Start with easy puzzles: If you’re new to Sudoku, it’s best to start with easier puzzles. These typically have more numbers already filled in, known as “givens,” and require fewer “logical processes” to solve the puzzle.

Look for the obvious: See if you can find rows, columns, or 3x3 boxes where a number can only go in one place. For example, if the row, column, or box already contains the numbers 1-8, the empty square must be 9.

Scanning: As you complete the puzzle, routinely check all the rows, columns, and boxes. Each number you place helps make subsequent numbers easier to identify. Be methodical and patient - sometimes, the numbers will fall into place.

Marking up: Don’t be afraid to write small pencil marks in the empty squares to help you keep track of possible numbers. For example, write down both numbers if unsure whether an empty square should be a 5 or a 6. As you progress, these marks will help you eliminate possibilities.

Process of elimination: Figuring out where a number cannot go is also valuable information. If you’ve marked up your puzzle, you can easily see when a number gets ruled out, which might tell you what other empty squares in the row, column, or box should be.

Double-check your work: If you have filled in a number, there should be a solid reason why that number is in that position. Regularly ensure each number appears only once in any row, column, or box.

Practice regularly: Sudoku is a game of logic rather than math and does not involve guessing! With consistent practice, you will develop or enhance the necessary skills required for more challenging puzzles. These skills include observation, logical reasoning, problem-solving, memory, concentration, and pattern recognition.