Lo Shu square

The Lo Shu square is a three-by-three magic square containing the digits 1 to 9, arranged so that every row, column and diagonal adds up to 15. Chinese legend has it appearing on the shell of a turtle that emerged from the Luo River. It underlies several feng shui methods and of a Chinese-inspired numerology in which the digits of the date of birth are placed in the grid to see which squares are filled and which are empty.