There is a general pattern for making magic squares with an odd number of rows.
The rules are:
- Arrange the numbers from smallest to largest.
- Place the smallest number in the middle square on the top row.
- Put succeeding numbers on a diagonal (going to the right and up).
- When you run out of rows (fall off the top), go to the bottom of the column in which you want to place the number.
- When you run out of columns (fall off to the right), go to the extreme left of the row in which you want to place the number.
- If the space in which you want to place the number is occupied, put the number in the space below the last occupied space.
- When you fall out the main diagonal, put the number in the space below the last occupied space (which should be in the second row
on the extreme right).
- If you are using consecutive numbers beginning with 1, you can find the magic number by the formula, (n(n2 + 1) / 2,
where n is the number of rows.
Examine the Magic Square below. See how it was created using the rules above.
Here is how the magic square was constructed:
- Arrange the numbers from smallest to largest: 1, 2, 3, 4, 5, 6, 7, 8, 9.
- Place the smallest number in the middle square on the top row:
1 goes in the middle square on the top row.
- Put succeeding numbers on a diagonal (going to the right and up):
5, and 6 go in a diagonal to the right and up.
- When you run out of rows (fall off the top), go to the bottom of the column in which you want to place the number:
2 runs out the top, so place it at the bottom of the 3rd column.
9 also runs out the top and is placed at the bottom of the 2nd column.
- When you run out of columns (fall off to the right), go to the extreme left of the row in which you want to place the number:
3 falls off the right, so it is placed in the extreme left square of row 2.
8 falls off the right, so it is placed in the extreme left square of row 1.
- If the space in which you want to place the number is occupied, put the number in the space below the last occupied space:
4 should go where 1 is, but since it is occupied, place 4 below the number 3.
- When you fall out the main diagonal, put the number in the space below the last occupied space (which should be in the second row
on the extreme right):
7 falls out the main diagonal, so it is placed below the 6 (in the extreme right cell of the second row).
- If you are using consecutive numbers beginning with 1, you can find the magic number by the formula, (n(n2 + 1) / 2,
where n is the number of rows.
Now try your hand at filling in the squares in a 5x5 square using the numbers 1, 2, 3, 4, ... 25. Make it a magic square.
What is the magic number?