I carry, attached to my keys, a Magic Square; the original can be found displayed on the Sagrada Familia Basilica in Barcelona Spain.  See: a later post titled “Sagrada Familia, Barcelona” for further speculation about this particular Magic Square:

MagicSquare2

This square is considered magic because adding each row, or each column, or either diagonal, or other groups of 4 numbers yield the same sum.

Here is how you can use a spreadsheet to create a Magic Square.

As with all spreadsheets; the Columns are A, B, C, D, & E and the Rows 1, 2, 3, 4, & 5.    Now; we enter values and perform calculations in your Spreadsheet:

You may enter any values you wish into the cells in the first row; A1, B1, C1, and D1.

Then enter the following formulas into your spreadsheet:

E1 = A1+B1+C1+D1

A2 = C1-2,  B2 = D1+2,  C2 = A1-2,  D2 = B1+2,  E2 = A2+B2+C2+D2

A3 = D1+1,  B3 = C1+1,  C3 = B1-1,  D3 = A1-1,  E3 = A3+B3+C3+D3

A4 = B1+1,  B4 = A1-3,  C4 = D1+3,  D4 = C1-1,  E4 = A4+B4+C4+D4

A5 = A1+A2+A3+A4,  B5 = B1+B2+B3+B4,  C5 = C1+C2+C3+C4

D5 = D1+D2+D3+D4, and E5 = A1+B2+C3+D4

If you wish, the cells in the 1st row can contain your birthday and another number.

For Example: Here is a Magic Square using the birthdate of September 29, 2008 and 0:

MagicSquare2

Try it with some birthdates!  Then ponder how it all works.

Now try entering other numbers, like zeros and negatives into A1, B1, C1 and D1.  Maybe it will be clearer now how it all works.

There is more information about Magic Squares HERE. You may notice that the Wikipedia article contains a ‘Birthday Magic Square’ which is very similar to your spreadsheet.  It uses the date convention of Day/Month/Year and it contains the Century value, yet it is using basically the same method of construction as your spreadsheet.

Incidentally; if your birthday is 5/4/8 (May 4, 2008), you may have noticed that South American relatives send their birthday wishes a month early on April 5th.  A reason for this can be found HERE, A very confusing lack of standards, which has led to many misunderstandings!

HERE is a web site that presents a Mind Reading trick using Magic Squares.