A Sudoku is a mind-challenging puzzle with basic rules, but requires you to think about which appropriate numbers should be placed in each 3×3 box. The rule is that every row, column, and 3×3 box must have the digits 1-9 with no repeats. There are some basic strategies to solve these puzzles.

Scanning consists of two techniques: crosshatching, counting 1-9 in rows, columns, and the 3×3 box. In crosshatching, scan the rows and determine the number by elimination. Then, scan the columns for the numbers. Check the numbers from nine to one. For the second technique, pinpoint the location of the number by counting in reverse until you find the remaining correct number.

You can always mark and make notes on the puzzle to help you solve it. One way is substituting all the possible numbers into the puzzle, and experiment with it. You can also use dots instead of numbers for substitution to indicate the number.

A Sudoku puzzle only has one solution, but it has many strategies to solve it. Try out a Sudoku puzzle, and challenge your mind. Solving Sudoku puzzles will improve your critical thinking.