Having tax woes? The Aztecs, who lived in Central Mexico and whose empire was particularly strong between the 12^{th} and 15^{th} centuries, shared your pain. They might not have had to fill out 1040 forms, but they did have to pay taxes, and the calculations were not simple, according to a paper published April 4 in *Science Magazine* which deciphered the mathematics of two codices from around 1540-1544. (“Aztec Arithmetic Revisited: Land-Area Algorithms and Acolhua Congruence Arithmetic” by Barbara J. Williams and María del Carmen Jorge y Jorge; see the abstract here.) Click to read more about Aztec math and taxes!