The first known example of a magic square comes from China. Legend tells us that around the year 200 b.c. the emperor Yu of the Shang dynasty received the following magic square etched on the back of a tortoise’s shell: The incident supposedly took place along the Lo River, so this magic square has come to be known as the Lo-shu magic square.

The even numbers are black (female numbers) and the odd numbers are white (male numbers). Translate this magic square into modern symbols.

This same magic square (called wafq in Arabic) appears in Islamic literature from the 10th century a.d. and is attributed to Jabir ibn Hayyan.