Sudoku

Sudoku is a puzzle with 9 rows and columns. The rows/columns are divided into 9 3x3 squares (you'll notice the bold lines; those are the things that separate the 3x3 squares.) that are indicated in bold lines. There are many kinds of sudoku. Sudoku was originally called Number Place. It originated in Japan, hence the name, and was a challenge similar to crossword puzzles, which don't work well with kanji.

No, you are supposed to use logic deduction to come up with the answers. It can seem impossible at times, but a sudoku should always be solvable using logic reasoning. Though a puzzle SHOULD be solvable using this technique , it is not always possible in more advanced puzzles. The most difficult levels require you to assume that a box is filled with one number or another. You pick one of the numbers, and then, you must follow the puzzle until you either solve it, or come to a impossible situation. Using the logical reasoning of "reductio ad absurdum", you then conclude that the number you picked WASN'T the correct number and start over from that junction point.

There are 9 rows and 9 columns. There is 81 individual squares in one grid.

It was invented by Howard Garn, an Indianapolis architect.

Undoubtedly the logic center. When people become skillful enough to start finishing Sudoku puzzles, they have a markedly improved logical deduction capacity for normal, everyday events. This is tremendously useful in discarding impossible remarks and theories.

Yes, of course Sudoku is copywritten. If it wasn't then people could go and steal it. If you don't believe me, you can go to Google and look it up. ( yes, Google is copywritten too!)

Any given Sudoku puzzle has just one solution. This is so long as the puzzle already comes with at least 17 digits already placed on the grid. If there are any less than 17 digits, then the puzzle has more than one possible solution, and therefore cannot be solved properly. The total number of possible combinations of digits on a standard sudoku grid is 6,670,903,752,021,072,936,960. However it can be argued that many of these combinations could be the same as another, only backwards or rotated. Factoring out all logical duplicates, the number of possible combinations drops to 3,359,232. This is essentially the total number of possible sudoku puzzles. * My Friend Dev Oneal has completed an 'Impossible Level' Sudoku puzzle, as I checked the answer given by the "Auto-Solve" feature and compare with his solution and have found both was correct but with different pattern. Hence, it could have more than 1 correct answer.

For example, have you ever watched TV and someone tried talking to you but you were in a zone? You didnt respond or realize they were talking. These "zombie" like trances are deleted eventually from your behavior if your mind exercises extensively. Sudoku is a stimulating and difficult mind exercise that can be extremely easy to those that just automatically figure the pattern in their mind. Those people are less likely to become "zombies". This takes years and years of dedication and not just with sudoku, but hundreds of thousands of mind boggeling puzzles.

CAUTION: If you're working on the New York Times puzzle for July 15 2007, I use some examples in the material below. I LOVE crossword puzzles and I do them daily. It's a joy when I finish one (I don't always...) There are some general ideas that I use, but it is mostly a matter of practice, and starting with puzzles that are not extremely difficult. First, use a pencil with an eraser. Go through the whole puzzle and get the 'easy' items you mentioned above. Never, never assume that the wonderful answer you just entered, you know, the one that shows what a good puzzler you are-- never assume that it is correct, and CANNOT be changed. Usually, when I trip up on a puzzle, it's because I won't let go of that 'special' answer that I KNOW is right, because I'm so darn clever. Be willing to let it go. I will often erase a word, just to clear my mind. This sometimes helps me solve connected words, even if the word I erased turns out to be right. I put it back in. Say that you have a word in mind, but you are iffy about it. Keeping the letters in mind, go through the 'across' clues to see if the letters you have in mind will bring quick answers to any of those. Example: The clue for 63 across is: "Showing deep embarrassment". I'm thinking of entering the word CRIMSON, but... I don't know... When I look at the clue for 63 down, "Like new bills", 5 letters, I think: If it begins with "C", hmm... "CRISP"! I think of this as evidence that "CRIMSON" might be right. Skipping to 65 down, the word beginning with "I" 5 letters, the clue is "Atahualpa's people". I think: Atahualpa sounds Mexican, or central American. Hmmm. Maybe a historic group, beginning with "I", 5 letters. I don't really know for sure, but I see that "INCA" fits. So I go ahead and put it all in. You don't really have to KNOW all the information. You just get good at making far-reaching, and sometimes weird connections. It's all part of the fun. I actually "know" maybe 10% or 20% of the information in a puzzle, even a puzzle I finish correctly. If I can't find any "evidence" that the word I have in mind might be right, I usually don't put it in. I have to feel comfortable with 2 or 3 "evidence" words, depending on the length of the word I have in mind. Clues that have question marks at the end have to be treated with special care. The question mark means that the clue is a TRICK. Sometimes (not always) the trick is associated with the puzzle's 'theme'. Here's the clue: "Hogwarts?" 18 letters. The clue invites me to think about Harry Potter, the movies, the characters, the plots, the "stuff", and all of that throws me off. It's not going to be that obvious. The answer is "INVOCATIONALSCHOOL". People who write these puzzles are DEVIOUS, maybe even EVIL. They want you to sweat, and work for success. A play on "Vocational School", and "Invocation". Sometimes the tricks have to do with how you read the clue-- Clue: "All your work may go into it". Answer: RESUME. If the clue itself contains an abbreviation, it is a hint that the answer may be an abbreviation. If the clue is asking for something in the past tense, the answer will be a verb in the past tense. Tense will match from clue to answer. These are just a few ideas. Keep practicing, and be sure to check the answers when you get them. As you check the answers, play with them in your head. Imagine how knowing that one word might have lead you to the others. Don't give up... You'll get a lifetime of pleasure from puzzling, and it will help keep your mind sharp!

5. There would be the 4 squares inside the grid, but also the one square which is the whole outside of the grid.

It is technically possible, but hard to do. It also depends on the difficulty - e.g, if it is an easy Sudoku, many of the boxes may already be filled, making it very unlikely, or often impossible.

don't think about that just play it for fun well maybe you learn to think fast

To complete the game in Sudoku, each column, square and row must have the numbers 1 to 9. No numbers can be repeated otherwise you can't complete the game.

because its cool like that!

35 minutes. Is the average time for someone to complete a puzzle Answer #2: If you go to websudoku, easy puzzle, it is considerably under 6 minutes on average. I take 12 and am out on the "fringes" of the distribution curve. Those Japanese are REALLY fast!

Well, there is a pattern to all of them... only one of each number in each column and in each row, and in each of the nine subareas. That's how you figure them out, by evaluating what could go in each square until you have it narrowed down and can be sure that only one number fits in a certain place... then you look for another, because hopefully that new number helped you narrow things down further, etc.

The direct anagram is FEELINGS.

Here are basic ones: attempt to fill in the ones, twos, threes, and so on focus on each box, row or column seperately use process of elimination

All the rules to regular sudoku apply as well as each number in each "cage" (the boxes with dotted lines) must be unique and add up to the number inside the cage.

You have to check "mouse click places number".

SUDOKU or Single Number, is a Japanese number puzzle that has swept through the world with the same gusto as the Rubiks Cube. Newspapers carry it, software houses, toyshops and bookshops sell a great deal of it. There is even a world championships. In the basic form it is a nine-by-nine grid divided into nine (sub-set) squares of nine squares. Numbers between one and nine are strategically placed by the compiler and the player is invited to fill in the rest. The rules are very simple, the game is incredibly addictive. Fill in all the squares with one number each of one to nine. There are to be no repeated numbers in any vertical or horizontal line nor a repeated number in any sub set (square) of nine squares. How hard can it be? Common variations of Sudoku are 8x8, 12x12 and 16x16 squares. Letters or shapes can be substituted for numbers. Other Japanese number puzzles include Kakuro, Kokonotsu, Kikagaku, Samu.

I certainly wouldn't recommend this for casual puzzle makers. It is incredibly tedious. Start with filling in a grid in such a way as to have the finished Sudoku result of only 1 instance of each number in a row, column and box. Double check your work carefully, as a mistake at this point will invalidate the entire puzzle! Start anywhere you like, and delete ONE number. Using "reverse Sudoku logic", erase another number that can be proven to be the only number that could go in the square that you erase. Keep erasing numbers that you can "provably show to be the only number that could go in the square given the 'current' state of the board AFTER you erase the number". When you can't figure out a way to erase any more numbers (not enough clues to force a move), you are done!

Yes. Sudoku is a mathematical game. Actually, I would not consider Sudoku a "mathematical" game ... it does however use some of the same logical problem-solving strategies that are applied in finding solutions to many mathematical problems. I teach middle school math and have found that some of my students who would rather skip the dreaded math class, are able to complete (and even enjoy!!!) Sudoku puzzles. :o)