[momtozandr]

How do make a magic 3x3 square for the number 11?

[ebaines]

A "normal" 3x3 magic square sums to 15 using digits 1-9. To get a different sum you can change the value of each square by 1/3 of the difference. For example to get the sums to be 18 instead of 15 you can add (18-15)/3 = 1 to each entry of the "normal" magic square. To get sums of 11 you can add (11-15)/3 = -4/3 to each entry. Note that this will result in a square that does not use integers.