Sudoku is a popular puzzle game played on a 9×9 grid. The objective is to fill the grid so that each row, column, and 3×3 sub grid contains the numbers 1 to 9. It’s a game of logic, requiring no math or guessing. Players start with some numbers already filled in and use deductive reasoning to complete the grid.
History of Sudoku
In the late 19th century, French puzzle setters played with number puzzles in newspapers. Le Siècle, a Paris daily, introduced a 9×9 magic square with 3×3 sub squares in 1892. Though not Sudoku, it shared similar features, with each row, column, and sub square totalling the same. La France, in 1895, refined it into a nearly modern Sudoku.
Each row, column, and broken diagonals contained numbers 1–9, with unmarked sub squares. These puzzles were popular in French newspapers like L’Écho de Paris until about World War I. Over the years, the modern Sudoku was inspired by this earliest type of the game.Â
How to Solve Sudoku PuzzlesÂ
If you are wondering how to solve Sudoku easily, here are some tips for you.
Start with What’s Given
Begin by filling in any numbers that are already provided in the puzzle. Look for rows, columns, or 3×3 squares that have the fewest empty cells, as they often provide the easiest places to start.
Scan Rows, Columns, and Squares
Look for numbers that appear only once in a row, column, or 3×3 square. If a number can only fit in one particular cell within a row, column, or square, place it there.
Use Pencil Marks
If you’re unsure about a number’s placement in a cell, lightly pencil in possible options (1-9) in the corner of the cell. As you progress, you can eliminate options as you find numbers that cannot fit in certain cells.
Look for Pairs and Triples
Scan rows, columns, and squares for pairs or triples of numbers that can only fit in specific cells. If two or three cells in a row, column, or square are the only ones where those numbers can fit, you can confidently place them there.
Focus on Single Numbers
Sometimes, finding just one number can unlock several other placements. Continuously scan the puzzle for opportunities to place single numbers, which can then help you solve for other numbers.
Practice Elimination
As you fill in more numbers, keep track of which numbers are still missing from each row, column, and square. Use this information to eliminate possibilities for empty cells.
Look for Hidden Singles
Pay attention to rows, columns, and squares where only one number is missing. By process of elimination, you can determine what that missing number must be.
Work Systematically
Approach the puzzle methodically, focusing on one row, column, or square at a time. This helps prevent overlooking possibilities and ensures thorough coverage of the entire puzzle.
Practice Regularly
Like any skill, solving Sudoku puzzles improves with practice. Regularly solving puzzles helps sharpen your logic and pattern recognition abilities.
Sudoku Rules to Keep in MindÂ
Fill the Grid
Sudoku is played on a 9×9 grid divided into nine 3×3 squares. The goal is to fill the entire grid with numbers from 1 to 9
No Repeating Numbers
Each row, column, and 3×3 square must contain all the numbers from 1 to 9, with no repetition. This means that every number must appear only once in each row, column, and square.
Start with Clues
Some numbers are already given in the grid as clues. These numbers cannot be changed and provide a starting point for solving the puzzle.
Logic, not Guessing
Sudoku is a game of logic, not guessing. Every number placement must be deduced using logical reasoning. Guessing can lead to errors and make the puzzle unsolvable.
One Solution
A well-designed Sudoku puzzle has only one possible solution. This means that there is only one correct way to fill in the entire grid following the rules.
Sudoku Variations
Sudoku comes in various forms besides the classic 9×9 grid. Variants include 4×4 and 5×5 grids. The World Puzzle Championship has featured 6×6 and 7×7 grids with different regions. Larger puzzles exist, like the Times’ 12×12 “Dodeka Sudoku” and Dell Magazines’ 16×16 “Number Place Challenger.”
In 2010, a colossal 100×100 puzzle called Sudoku-zilla was published. “Mini Sudoku,” found in USA Today, is a 6×6 variant using numbers 1-6. “The Junior Sudoku” caters to younger solvers, appearing in newspapers like The Daily Mail. Each variant maintains the same basic rules as standard Sudoku.
