The concept of this Japanese-style number game is rather simple: Every vertical and horizontal line, and each 9-number square, must contain all the numbers from 1 to 9. There are, I understand, advanced versions of the game that contain more numbers - always multiples of 9 - but the standard version is enough for me.

No doubt there are various methods for finding the solution, but I'll outline the one I use. And hope it will be enlightening to those readers who won't attempt the game for lack of understanding and tenacity. Might I remind you too that the solution is always given, and I often "cheat a little," when a particular square has two or more possible answers and no obvious clues.

There appear to be several "levels" of play. The beginner's level, the one I'd recommended a novice start with, has the greatest numbers given. Intermediate has fewer, often just two or three per line. Advanced has the fewest, frequently only one or two, or even none, per line. I'll try a solution to a "beginner" version as an example.

I have lettered the horizontal and vertical lines, on the sample I've included, for clarification purposes. I use a piece of scratch paper to identify the missing letters, always the first step, and done line by line.

Start with "B", second horizontal line across. A quick scan shows the "B" line lacks 1, 4 and 9. Line "P", which intersects with "B" at this point, already has 4, and the upper right square has the number 1. So the "P" square on the "B" line must be 9. That leaves 1 and 4. The "J" line (vertical) already has a 4, so this square must be 1. That leaves 4 for "M."

Next we have the "H" line, which lacks 1, 3, 5 and 9. Scan the vertical columns intersecting this line. The most promising is "L." This column contains 3 and 9, leaving only 1 and 5 as possibilities. Number 5 is already present in the lower left square. So the "L" column must be 1. The numbers 3, 5 and 9 are not so clear, although "O" cannot be 9, because 9 is already present in the lower center square. Also, "R" cannot be 3, because it's already present above. In this case, we "cheat" and look at the answers. Clearly, if we assign 3 to the "O" square, that leaves only 5 and 9 for the last two. Again, look at the answers and determine that 9 are in the "Q" column and 5 in the last.

The next prospect is the vertical column "J", which lacks 3, 7, 8 and 9. The numbers 7 and 8 are present in the "P" line, leaving only 3 and 9. Again, we sneak a look at the answers, and find that "D" is a 3. Another look shows that "A" is a 9. Number 8 is present in the upper left square, so "C" must be 7. That leaves 8 for "F."

Letter "M" lacks 1, 2, 5 and 9. Numbers 5 and 9 are present in line "I", bottom horizontal. That leaves 1 and 2, and a quick glance shows it's a 2. With a 9 already in the "G" column, that leaves only 1 and 5. A check of the answers shows "G" is a 5. That leaves 1 and 9 for "C" and "E." A peek at the answers shows that "E" is a 1, so "C" must be a 9, also confirmed.

Letter "O" is next, and a check shows 1, 2, 5 and 6 missing. Number 5 is present in the upper middle square, which means "A" and "C" cannot be 5. There's also a 5 in the "G" line. So 5 must be in the "E" line. Number 2 cannot be in the "G" column and 1 cannot be in the "A" line. A quick "sneak peek" shows "A" is a 2 and "C" is a 1. That leaves a 6 in "G."

Try "R" next. The column is missing 4, 6, 7 and 9. Numbers 6 and 7 are present in the "G" line and 9 is already in the lower right square. Therefore, "G" must be a 4. The numbers 7 and 9 are out for the lower, right-hand corner, "I" so it must be a 6. Number 7 is no good for the "D" column, so it must be a 9. That leaves 7 for the "F" column.

Next best is "A" which is missing 4, 5, 6 and 7. The numbers 5, 6 and 7 are already present in the "K" column, so the only prospect left is 4. The numbers 5 and 7 are present in the upper middle square, and that leaves 6. Number 7 is already in the "Q" line, and that leaves 5. Number 7 is for "P."

The rest are easier. Letter "C" for instance, lacks only 2, 6 and 8. The upper left square lacks only a 2. And the upper middle square is only missing an 8. And the upper right lacks a 6. That completes the "C" column.

Letter "G" lacks only 1, 3 and 8. A quick check of the answers shows that 3 fits in the "K" line. Number 8 is already present in the "N" column, so that one must be a 1. And the 8 goes in column "P."

Letter "I" lacks a 1, 4, 7 and 8. But the lower middle and lower right-hand squares only lack 7 and 1, respectively. That leaves 4 and 8. But there's a 4 in the "K" line, so that one must be 8 and the 4 in the "L" column, which also completes the lower left square.

Letter "K" is missing 1, 2 and 9. Numbers 1 and 2 are already in the "E" column, so that one must be a 9. There are no clues for "D" and "F" so, a peek at the answers show them to be 1 and 2, respectively.

Letter "D" column is missing 2, 4 and 5. Number 4 is present in the "N" column and also in the middle square, as well as 5. So "N" must be a 2. Number 4 is present in the "F" column and 5 in "Q," so "P" has to be a 5 and 4 in "Q" and 6 in "L."

That leaves "E" and "F." Letter "E" is lacking 3, 6, 7 and 8. Numbers 6, 7 and 8 are present in column "N" so that one's got to be a 3. Numbers 7 and 8 are already in column "P" so that one must be a 6, and then number 7 in "L" and 8 in "Q."

The center square is lacking only one number and it's a 9. That means that the "F" column is only missing 1, 3 and 5. Numbers 1 and 3 are in "L" so that must be a 5. Numbers 3 and 1 are present in "P" and "Q" so just exchange them, placing 1 in "P" and 3 in "Q" and it's done.

As you can see, the further along you get in the game, the quicker and simpler it becomes. And don't feel reluctant in "cheating" when you need to, or to double-check your answers. Congratulation for completing the game and continued success on subsequent ones!