What is sudoku? Here's how to play the math puzzle and some tips to solve one.
Daily puzzlers would be quick to tell you that sudoku, Wordle’s mathematical cousin, is not as easy as it looks. The small grid, found often next to a word scramble or comic strip in a print newspaper, demands focus and big picture thinking.
How do you play sudoku? What are the rules? We unpack the puzzle for beginners below, and give a little context on brain benefits, and name origin.
Play Sudoku online: USA Today puzzles
Play the crossword while you're at it: USA Today online crossword
What is sudoku?
Sudoku is defined by Merriam-Webster as a 9-by-9 grid puzzle in which the grid is divided into 3-by-3 boxes. Every row, column and box must contain the numbers one through nine, no repeats.
Sound like a jumble of words? Here is an example of solved sudoku as a visual aid.
How do you play sudoku?
If you’re a beginner, a lot of sudoku puzzling is trial and error (so start with a pencil, not a pen.)
Most sudoku puzzles come with a few of the boxes already filled in, so you can use those freebie clues as a jumping off point for solving and work backwards. The fewer numbers already filled in the more difficult it will be.
Outside of that, there is no straightforward "how to play" sudoku guide. The only hard and fast rule is not to repeat numbers. Suduku.com advises using the process of elimination, or deductive reasoning.
Solve our online jigsaw puzzle: Play now.
What are the 3 rules of Sudoku?
Each row should have numbers 1-9, no repeats
Each column should have numbers 1-9, no repeats
Each 3x3 quadrant should have numbers 1-9, no repeats
Bonus rule: Mathematically this means the sum of each of these categories should be 45.
What type of math is sudoku?
Solving a sudoku puzzle actually relies more on logic than math. There is no real arithmetic operation happening, save for subtraction of the numbers already used from those possible for future use.
An article from the Department of Mathematics at Cornell University explains, “one needs to use a combination of logic and trial-and-error.” More math is involved behind the scenes, for the puzzle masters designing different sudoku grids.
Try our online word search: Play now.
What are the benefits of sudoku?
This puzzle, like any game of logic, is a workout for your brain. Healthline reported in May of 2019 on a cross-sectional study showing participants who engaged in games like sudoku and crosswords performed better on subsequent tests.
The study went so far as to say those who do puzzles like sudoku have brain function that is equal to 10 years younger than their actual age. More research is needed to definitively prove this conclusion, study authors clarify, but in the meantime, not a bad idea to keep up with your puzzling to sharpen cognitive skills!
Other tips for a sharp mind: Try these easy mind games to improve your brain function and help prevent disease
Where does sudoku get its name?
A brief history, as provided by the Cornell University mathematics department. American Howard Garns in 1979 invented sudoku as we know it, and published it originally as a puzzle in Dell Magazines with the name "Numbers in Place."
Maki Kaji of Japan then published the grid in Nikoli, his puzzle company’s magazine in 1984. He is the bestower of the modern name of sudoku, meaning "single numbers” in English.
This article originally appeared on USA TODAY: What is sudoku? How to solve, rules, benefits to the brain, explained.