| Sudoku, or number placement, puzzles are sweeping | | | | middle cube has a number one as one of the given |
| the country. Even though the game involves | | | | numbers. That means that the number one you need |
| numbers, it is not mathematical. And people who feel | | | | to place must be located in the left or right cube. |
| they don't have a good vocabulary will choose them | | | | Instead of 9 potential placements, you now have |
| in preference to crossword puzzles. Soduku is nothing | | | | only 6.After you have determined all the missing |
| more than logic.Howard Gams is given credit for | | | | numbers, you will find that you have many with two |
| inventing the puzzle in 1979. His puzzles never caught | | | | or three possibilities. Hopefully you will be able to |
| on in this country but became an instant success in | | | | write these possibilities in the squares. The best you |
| Japan. Now it is carried by more newspapers than | | | | can hope for is to have two contiguous squares with |
| crossword puzzles.Soduku is a nine-by-nine cubical | | | | only two possibilities. In the top rank, squares one |
| grid. When properly completed, each of the rows and | | | | and two are either a six or an eight, but you can't tell |
| files will contain all the numbers between 1 and 9 as | | | | which. You still have learned a great deal of |
| will each of the 3 X 3 cubes comprising the whole. | | | | information because it means that those two |
| The puzzle will appear as a completed grid with | | | | numbers can't appear in any of the other empty |
| certain numbers missing. When read across and | | | | squares across that rank. As I suggested before, |
| down, each of the three contiguous inner cubes will | | | | every time you find a "hard number," one that |
| have a different digit in a different position. For our | | | | cannot be placed anywhere else, fill it in with |
| purposes we can designate these rows as ranks and | | | | pen.Another way to come up with information is to |
| files. Ranks run horizontally across the puzzle and | | | | use the "what if" method of placing numbers. Let's |
| files, vertically. If, for example, the number one | | | | say that you have a six in the second rank of the |
| appears in rank 1 in cube one and rank 3 in cube 2, | | | | small cube in the upper left corner. Even if you have |
| the third one must necessarily appear in the second | | | | no other information where the other two 6s are |
| rank in cube 3. This would seem to imply that it could | | | | located, you you know that the other 6s must be in |
| appear in any of three positions in the second rank, | | | | first and third ranks. By placing it in the first rank, you |
| but most often, there will already be a number in one | | | | will then have to locate the last placement in the third |
| position, leaving a choice of two possibilities. Let's | | | | rank of the remaining cube. By testing the |
| assume you have a choice of two positions.The next | | | | placements you will often run into a contradiction in |
| step is to check the files. If by some chance a one | | | | one of the ranks or files. If you don't shrug your |
| appears in one of the files of your choices, you now | | | | shoulders and try placing another number and see |
| know the numeral must be placed in the other. This | | | | what happens.Kerep at it. Sooner or later you will |
| simple cross check should be your first step in solving | | | | have filled in most of the numbers. On more than |
| the puzzle. Anytime you find a HARD number, one | | | | one occasion I have run into a contradicition on the |
| you have logically determined cannot be another, I | | | | very last number. There's nothing to do about it but |
| recommend you write it in with a Pen. This will save | | | | back up and start again. Patience is the greatest skill |
| unnecessary erasures when you make an inevitable | | | | required to solve thse puzzles.Sooner or later, you, |
| mistake.Your second step should be to scan each of | | | | your pencil the paper or the puzzle will call it quits. |
| the smaller cubes for their missing numbers. Usually | | | | Let's hope it's the puzzle.John Anderson is addicted to |
| you will be able to place one or two numbers by the | | | | puzzles in any of their forms. They play a crucial role |
| rank-file cross-checking. After you have done that, | | | | in his novel, The Cellini Masterpiece, written under the |
| read across each of the ranks and files to determine | | | | pen name of Raymond John. If you have a question |
| the missing numbers. Let's say that you are missing a | | | | or comment for John, please log on to You also may |
| number one in the top rank and you have missing | | | | read the first chapter of The Cellini Masterpiece at |
| numbers in all of the smaller cubes. Let's say that the | | | | the site. |