Sudoku Rules
The board has 9 x 9 fields which can be considered as:
1. 9 rows of 9 fields each
2. 9 columns of 9 fields each
3. 9 groups of 9 fields each
at the start, some fields contain a number 1 to 9.
The player must place a number, 1 to 9, in the open fields
considering following restrictions:
1. each number 1..9 must appear just once in a row
2. each number must appear just once in a column
3. each number must appear just once in each group
A SUDOKU puzzle is solved if all fields are filled like this.
Essays on Sudoku puzzles
Eliminate Sudoku FrustrationEvery person who has ever done the Sudoku puzzle over time has at some point become frustrated. You get to a situation where you just can’t see any headway. There seems to be no clues as where to go next. And I know from personal experience that staring blankly at the puzzle waiting for a solution to hit you between the eyes just never happens. There are two keys to getting past the frustration.
The first key is to understand the thinking of the Sudoku creator or puzzle writer (or what ever you want to call him). He wants you to get frustrated. That is his goal. Depending on what level of Sudoku you are attacking he will use a different number and variety of tricks and roadblocks to make it difficult to find the final solution. When your level of frustration rises, so does his level of satisfaction. Conversely when you get to a roadblock or dead-end and you know that this is part of his plan, then it is easier to stay calm and find the solution.
The second key is to have a plan of attack or strategy for these roadblocks. Just knowing that they are there is fine but not finding a solution can be very frustrating in itself. So having an orderly strategy you can use to find a way past the roadblock is imperative. If you remember the Rubik’s cube, it was very frustrating to solve. But once you could solve one face then the other five faces could be solved by repeated using just four sequences of moves. The difficult part was finding those moves but once found and remembered then the cube could be easily and repeated solved. For solving Sudoku, I personally use the dot-dish-dash technique. It is a combination of three overlaying marking strategies that enable anyone to solve any level Sudoku they wish to tackle. I am sure there are people of high enough IQ that they can solve the hardest Sudoku in their head without any markings on the page at all. I am, unfortunately, blessed with only an average IQ and therefore use the marking to help me to a solution. The dot-dish-dash markings are relatively unobtrusive, easy to implement and interpret.
Now when I get to a roadblock I see it as the challenge of me against the puzzle maker. And with a good strategy its not whether I can break down the strategy of the puzzle maker but how fast and cleanly I can do it?
Kevin Meates maintians the site
http://www.sudoku-strategy.comWinning Strategies For SudokuSudoku is a logic-based placement puzzle with an aim to enter a numerical digit from 1 through 9 in each cell of a 9X9 grid. Although the first sudoku puzzle was published in the U.S., it did not attain international popularity until 2005. Solving sudoku puzzles generally involve a combination of three processes. These include scanning, marking up and analyzing. Following is a brief guide to solving soduku.
1. Scanning: Scanning generally takes place not only at the outset but also throughout the solution and consists of two basic techniques. (a) cross-hatching involves scanning rows or columns to identify which line in a particular region may contain a certain numeral by a process of elimination. (b) counting 1-9 in regions, rows and columns to identify missing numerals. Counting based upon the last numeral discovered may speed up the search.
2. Marking Up: Once no further numerals can be discovered, sudoku players often find it necessary to mark potential numerals in blank cells. This can be done by actually writing in numerals or dots to represent potential numerals.
3. Analysis: Two main approaches to analysis include “candidate elimination” and “what if.” Candidate elimination; includes successively eliminating candidate numerals from one or more cells to leave just one choice. After each answer has been achieved, another scan may be performed, usually checking to see the effect of the contingencies. What if ; using the what if approach, a cell with only two candidate numerals is selected and a guess is made. The steps above are repeated unless a duplication is found or a cell is left with no possible candidate, in which case the alternative candidate is the solution.
Ideally, one needs to find a combination of techniques which avoids some of the drawbacks of the above elements. The counting of regions, rows and columns can feel boring. However, sudoku is a fun and engaging game that can sharpen the mind and keep one entertained for hours.
Roxane Manning provides a free sudoku puzzles related information at
http://sodoku101.blogspot.comSudoku - The Hottest Puzzle Craze Since Rubik's CubeSudoku is the addictive number puzzle that has taken the UK by storm and is now taking over the rest of the world. Since it first appeared in The Times in late 2004 its popularity has grow so that it appears in most UK newspapers and has spread to countries from India to Canada, Australia to South Africa.
So what is Sudoku all about? Sudoku is played on a nine by nine grid which is divided into nine smaller squares. The object of the puzzle is to fill in the digits from 1 to 9 so that it appears only once in each column, row and small three by three square. You are given some of the numbers and you have to use logic and deduction to find the position of the other numbers.
Simple? Well, it depends! A Sudoku puzzle can vary from easy to absolutely fiendish. Certainly the more numbers you are given to start off with, the easier the puzzle, but it also depends on which ones the puzzle setter offers. Traditionally there should be no more than 30 numbers given.
Sudoku first appeared in a US puzzle magazine in the late 1970s, but was then picked up by Japanese publisher Nikoli who dubbed it Su Doku or ‘Solitary Square’ and the puzzle-hungry Japanese loved it. From there it was discovered by The Times and the rest is history.
Sudoku is solved simply by logic; there is no maths required. You may at first be able to fill in a couple of numbers where it appears in every column and row but one. Next you may need to mark up possible candidates in the empty squares until only one possibility remains. Like so many puzzles there will be times when you stare hopelessly and others where the answers jump out at you.
The sudden popularity of Sudoku may be due to many things. It requires just enough brainwork to give a feeling of satisfaction when the puzzle is complete, without taking up huge amounts of time and it requires no special knowledge unlike for instance crosswords, which may require a wide vocabulary.
For hardcore Sudoku fans there are now even more difficult versions. There are sixteen by sixteen square versions which include letters as well as numbers, and a three dimensional version called the Dion Cube.
There are benefits to doing Sudoku puzzles too – the sort of exercise which the brain gets from logic puzzles can help to stop memory decline, make you smarter and even halt the progress of Alzheimer’s disease. Teachers are even giving simple versions of the puzzles to pupils to help develop their logic skills. So next time you see one of those nine by nine grids in your newspaper, give it a go. Your brain might just thank you!
Jacqui O’Brien is a Sudoku fan and the webmaster of
http://www.sudokuonline.co.uk, where you can find all the latest news and information on Sudoku as well as the best online Sudoku games and solvers.
The Trick To Winning At SudokuSudoku is one of the hottest trends in games and entertainment. The interest in this Japanese number crossword puzzle is absolutely at a fever pitch. The rules are simple - fill in the squares so that all numbers are represented only once per row. Simple rules, difficult to follow. What makes Sudoku almost addicting is the consistent challenge of finding the right match. The trial and error matched with a pre-planned strategy based on the clues you're provided make success possible for everyone. And of course it helps that there are different game levels available. So you can start with, or always go back to, the easiest level in order to gain an understanding of how the game works and what strategies work best for you. And unlike crossword puzzles, which are popular in their own right, Sudoku does not require an infinite knowledge of words or a long-term commitment to figure a puzzle out. And the frustration level stays low because one can always go back to the most basic level and focus on speed rather than mere completion. In a 5-30 minute time period, one can play a game or a few, be challenged intellectually, get the satisfaction out of completing a puzzle, and walk away refreshed to go use their brain in another matter. And with the online resources and local clubs and competitions, the Sudoku experience is only becoming more popular. School children use it in their classroom to practice addition, number patterns, and logical thinking - while many in assisted living programs have incorporated Sudoku into their regular bingo rotation.
The best thing about Sudoku is it provides an equal playing ground for everyone. Four year old kids, elderly adults, PhDs in math, and those who don't speak English can all play the same game, with varied difficulty levels, and get the same level of satisfaction from it.
About the Author:
Dave Lloyd has published an online guide to learning about the Sudoku Japanese number puzzle game at
http://www.sudokuhere.com
Boost Your Child's Brainpower With Sudoku!In less than a year the Sudoku bug has infected huge numbers of the UK population, and it is fast spreading across the world! Why has a simple logic puzzle become so popular, and how can your kids benefit?
Sudoku puzzles were first published in the US in the 1970s and are sometimes known as "Number Squares". They have been popular for many years in Japan, where the name "Sudoku" (meaning "single number") was coined. The current craze was started late in 2004 when a UK newspaper started publishing the puzzles. Within weeks the puzzles were picked up in other newspapers and Sudoku became the pastime of choice for commuters, parents – and even kids!
From a parent’s point of view, Sudoku puzzles are perfect for long journeys, waiting rooms, and rainy afternoons. They are being found more and more in the classroom as teachers wake up to their benefits and use them as time-fillers for children who finish early, as whole class activity, or as “homework”. Indeed, the UK government-produced Teachers magazine has recommended that Sudoku puzzles are used in the classroom as brain exercise!
As well as developing your child's logic and reasoning skills and concentration, Sudoku puzzles, if done at the right level, build your child's confidence. Children of all abilities enjoy the challenge of a Sudoku puzzle, if the puzzle is age-appropriate. Bear in mind that many of the puzzles published in newspapers are too difficult for younger children, so it is worth seeking out puzzles made especially for kids. Children as young as five years old can try the 4x4 grids, then build up to the 6x6 grids and finally the traditional 9x9 grid.
Why are Sudoku so appealing? Firstly, although Sudoku grids usually use numbers, your child does not need mathematical skills to solve the puzzles – only logic. Using logical reasoning appropriate to his/her age, your child decides how to place numbers into a Sudoku grid. There is only one correct answer for each puzzle, no guessing is necessary, and the rules are easy to learn. The more puzzles you do, the better you become. Each puzzle typically takes a child about 20-30 minutes to complete, and gives them a real sense of satisfaction when finished!
And that, really, is the secret of their popularity. You feel good when you finish one! And then you want to try another one, and another ….
About the Author:
Lindsay Small is the owner of Activity Village, packed full of fun and educational activities for kids. Do you have children aged 2-10? Visit
http://ww.ActivityVillage.co.uk to find free kids crafts, printables, educational resources, worksheets, coloring pages and puzzles, jigsaws and, of course, Sudoku puzzles!