When was sudoku invented, and who invented it?
Some accounts attribute the game to a Swiss mathematician, Leonhard Euler in the late 1700s. The four lines that create the 9x9 blocks were added later. The name Sudoku originates from Japan and is translated to mean solitary number. A very similar puzzle called Number Place was published in America in the late 1970s and in 1984 a Tokyo publisher saw the Number Place puzzle and began producing a Sudoku magazine.
Can a puzzle have more than one correct solution?
No. Every Sudoku puzzle has one and only one correct solution.
Can I change or move the numbers that are already on the puzzle when I start it?
The pre-filled boxes are sometimes referred to as "givens". No, you cannot change or move any of the givens in a Sudoku puzzle.
Do I need to be smart in math to be able to get the right answer?
No. After all, you’re not performing any operations on the numbers, like adding, subtracting or multiplying. Sudoku is solved by using logic and patience. It’s basically a process of elimination.
Isn’t sudoku really a trial and error puzzle?
No, it’s not a trial and error game, although some players say they use trial and error. The best way to solve the puzzle is to eliminate all but one possible number for each box – guessing can actually waste time.
When I start a new puzzle, where should I begin?
You can solve a Sudoku puzzle in any order or fashion you like. Many players like to look for the rows, columns, and blocks that contain the most "givens". With experience, your eye becomes trained to see patterns and better starting points.
What do I do if I make a mistake and end up with the same two numbers in a row, column or block?
You only have two choices – either start over or try to find and correct the mistake. Sometimes trial and error is used here, especially when reversing a wrong placement.
Are there other variations of the game besides the standard 81 box grid?
Yes, there are several variations. Examples: Diagonal Sudoku – the two main diagonals must also contain numbers 1 through 9. High Five Sudoku – uses five overlapping 9x9 grids. Even-Odd Sudoku – some cells must contain only even or only odd numbers.
How long does it take to complete a puzzle?
It depends on the player’s skill and the puzzle’s difficulty. Easy puzzles may take a few minutes. Harder puzzles or variants may take hours. You’ll get faster with practice.
What kind of person would make a good sudoku player?
Just about anyone. Sudoku requires logic and patience, not math skills. With practice, anyone can get better at solving.
Are Sudoku tournaments held?
Yes. The first World Sudoku Championship was held in 2006 in Lucca, Italy. Players from around the world solved 45 puzzles over two days. Many variations of Sudoku were used in the competition.