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