Why is Killer Sudoku called that?

Killer Sudoku is a variation on normal sudoku. All the typical sudoku rules apply: each digit must appear exactly once in each row, column, and box. But in addition, there are these things called "killer cages" with a little number in the top lefthand corner. The digits in these cages must add to the provided number.

What is the difference between Sudoku and Killer Sudoku?

Killer Sudoku is a mix of Sudoku and Kakuro. Your goal is the same as in regular sudoku: fill every row, column and 3x3 region with the numbers 1-9 once. The difference is how you arrive at those numbers. In killer sudoku, no numbers will be filled in at the start.

What is the 45 rule in Killer Sudoku?

Rule of 45

Each sudoku region (i.e., row, column, or nonet) contains the digits one through nine. Thus, each sudoku region has a total value of 45. If S is the sum of all the cages contained entirely in a region, then the cells not covered must sum to 45-S.

What is the history of Killer Sudoku?

History. Killer sudoku puzzles were already an established variant of sudoku in Japan by the mid 1990s, where they were known as "samunamupure." The name stemmed from a Japanized form of the English words "sum number place." Killer sudokus were introduced to most of the English-speaking world by The Times in 2005.

Is Killer Sudoku harder than Sudoku?

There's a common opinion that even though its name contains the word “killer”, it is actually easier than the classic sudoku. Well, not if you play a hard Killer Sudoku. Hard Killer Sudoku levels have the same rules as any other level, the only difference is very few numbers on the grid from the beginning.

Killer Sudoku Tutorial

Is Killer Sudoku good for the brain?

Solving Killer Sudoku online has a lot of benefits. Daily Killer Sudoku sessions are said to help you train your brain, improve memory, concentration and logical thinking. If these practical reasons aren't enough for you, Killer Sudoku is a fun time-killer too!

What is the hardest Sudoku puzzle in the world?

A Finnish mathematician claims to have designed the world's most difficult Sudoku. The numerical puzzle took Arto Inkala three months to design, and it has only one solution - one that only the sharpest minds will discover, he told the Daily Telegraph.

Is there math behind Sudoku?

To solve a Sudoku puzzle, one needs to use a combination of logic and trial-and-error. More math is involved behind the scenes: combinatorics used in counting valid Sudoku grids, group theory used to describe ideas of when two grids are equivalent, and computational complexity with regards to solving Sudokus.

What is greater than Killer Sudoku?

The “Greater Than” Killer sudoku take killer sudoku to a new extreme. Some of the cages have no sum value attached. You must determine what the individual cells in the cage sum to by looking at surrounding regions. If there are relations between the cages (e.g., >, <, or =), the cages will obey those relations.

What is diabolical Sudoku?

Classic sudoku: fit the numbers in the grid so that each row, column and square contains the numbers one to nine once only. If you think it sounds simple then try our diabolical sudoku to see how hard it can be. All Sudoku Diabolical Puzzles.

What is Sudoku rule of 1?

Rule 1 - Each row must contain the numbers from 1 to 9, without repetitions. The player must focus on filling each row of the grid while ensuring there are no duplicated numbers. The placement order of the digits is irrelevant. Every puzzle, regardless of the difficulty level, begins with allocated numbers on the grid.

What is the hidden triple rule in Sudoku?

"Hidden triples" applies when three cells in a row, column, or 3x3 block contain the same three Notes. These three cells also contain other candidates, which may be removed from them.

What to do when stuck in killer sudoku?

If you get stuck when solving killer sudoku, or even right at the start, look for instances where you can apply the rule of 45 to make progress or possibly just narrow down the possible values for squares.

What is the least clues in Sudoku?

Sudoku fanatics have long claimed that the smallest number of starting clues a puzzle can contain is 17. Now a year-long calculation proves there are no 16-clue puzzles. Sudoku is a number puzzle consisting of a 9 x 9 grid in which some cells contain clues in the form of digits from 1 to 9.

Can Killer Sudoku have multiple solutions?

A Sudoku puzzle can have more than one solution, but in this case the kind of logical reasoning we described while discussing solving strategies may fall short. There are examples of rank-3 Sudoku puzzles with 17 givens that are well-formed.

Does Sudoku keep brain sharp?

Sudoku requires attention of the subject to analyze the grids and fill in the numbers; basically it requires no math but is based on logic [1]. Solving puzzles has long been thought to keep the brain healthy [2] and has been shown to delay the onset of dementia [3].

What is the best order to solve Sudoku?

The easiest way starting a Sudoku puzzle is to scan rows and columns within each triple-box area, eliminating numbers or squares and finding situations where only a single number can fit into a single square. The scanning technique is fast and usually sufficient to solve easy puzzles all the way to the end.

What is the most clues in Sudoku?

An ordinary puzzle with a unique solution must have at least 17 clues, but this is not mathematically proven. There is a solvable puzzle with at most 21 clues for every solved grid, with the largest minimal puzzle found so far has 40 clues in the 81 cells.

What is the best algorithm to solve Sudoku?

The simplex algorithm is able to solve proper Sudokus, indicating if the Sudoku is not valid (no solution). If there is more than one solution (non-proper Sudokus) the simplex algorithm will generally yield a solution with fractional amounts of more than one digit in some squares.

Is Sudoku high IQ?

From this case study it can be concluded that an individual who is skilled at solving Sudoku puzzles likely has a high general IQ. The results of the weak correlation between Sudoku scores and the WAIT test indicates that in some cases a high Sudoku doesn't necessarily mean a high general IQ.

What happens if I solve a Sudoku daily?

Sudoku keeps your brain active and reduces the risk of Alzheimer's, a most common cause of dementia that affects a person's thinking and behavioural skills. Stimulates your mind: The game works on your logical thinking process as you are absorbed in solving a puzzle and eventually improve your number skills.

Is Sudoku an IQ game?

Sudoku is a great example of a game of logical thinking skills that helps evaluate one's cognitive ability. If you're looking for how to challenge your brain or how to test your IQ, then you've come to the right place.

How fast can the average person solve a Sudoku puzzle?

It is believed that the average Sudoku player spends approximately 20 minutes solving a typical Sudoku puzzle. For very hard puzzles, that number can be much higher. While the game itself can be challenging and complex, several strategies can be used successfully to find the solution.

What is the most addictive puzzle since Sudoku?

Invented by Japanese mathematics teacher Tetsuya Miyamoto in 2004, KenKen is an elegant and rich logic puzzle with a few easy-to-understand rules, which helps explain why New York Times Puzzle Editor Will Shortz called it “The most addictive puzzle since Sudoku.”

Are there unsolvable Sudoku puzzles?

Realistically, no! There are 6,670,903,752,021,072,936,960 possible solvable Sudoku grids that yield a unique result (that's 6 sextillion, 670 quintillion, 903 quadrillion, 752 trillion, 21 billion, 72 million, 936 thousand, 960 in case you were wondering). That's way more than the number of stars in the universe.