Learn to Play Sudoku - The Ultimate Game Of Logic
Sudoku is a game of logic to which you can get very addicted, very easily. Sudoku is a 9 x 9 grid subdivided into nine 3 x 3 grids with 81 squares in all. The object of the puzzle is to place a number between 1 and 9 into each square on the grid. The trick is that only one of each number can be on the same line and in the same sub-grid. Lines go horizontally and vertically.
It is very easy to grasp the object of the game but not always as easy to complete successfully. Sudoku is a test of logic. You do have to use your reasoning powers and a lot of patience. If you have never used logic puzzles before, the first one may take quite a long time. When you have mastered how it all works, you will soon be able to complete one in minutes. However, be warned, it is addictive.
As with any logic puzzle, there has to be a starting point. Find that and you’re on your way. The rest is just a process of elimination.
How to find the starting point – Learn to Play Sudoku
Somewhere on the grid is a space that only one number can fit into based on the numbers in the corresponding lines. Some people look for all of the possible numbers that go into a square and write them into that square. I find that it clutters the workspace and causes confusion.
This is how I do it and I can finish one in no time flat. Starting in the top left grid, I select the first number in that grid and look for the same number in the two grids below. If the number is in one of the grids, the process of elimination demands that the number must go in the third row of the grid that does not have that number.
Using the example grid we can see that 5 and 3 do not have corresponding places in either of the grids below. The number 6 does. It is in row 1 and row 2, we can therefore deduce that the missing 6 must go in the third row.
We now look to the grids to the right to see if the number 6 is there. In this case we struck lucky because it was in the upper row of the middle grid and the lower row of grid on the right. The only logical place for the missing number six is in the center square of the third row.
We can now eliminate the number 6 from the grids on the right hand side. We can already see that there is a 6 in the eighth and ninth columns of the top right and middle right grids so the only logical position is in column 7, row 8 or 9 of the bottom right grid.
Look at the middle grid on the bottom. There is only one row to put the number 6. It cannot be on the top row because there is already a 6 on that row and it cannot be the middle row because that is filled in. The 6 must go on the bottom row of the middle grid. That leaves only one place for the 6 to fit in the bottom right grid, and that is column 7 row 8.
When I have finished all of the easy numbers, I find it easiest to go back to grid 1 and continue with the next number. I then go over all the numbers again looking at the horizontal rows.
When the first grid is exhausted, I go to the next grid and begin the same exercise.
As the numbers begin to fill in, you will notice that at least one of the squares or grids may have only one or two free squares. Concentrate on those. If there is only one space available, fill it in.
Soon you will find that all of the squares are filling in. I suggest using a pencil for the first two or three games so that you can erase any errors.
When you complete one successfully, start timing how quickly you can finish and try to beat your own record.
I told you Sudoku is addictive.
Thank you to Ian Patterson for this "Learn to Play Sudoku" article.
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