“As I was going to St. Ives I met a man with seven wives..” You may know this singsong quiz, But what you might not know is this: That it began with ancient Egypt’s Early math-filled manuscripts. It’s true. That very British-sounding St. Ives conundrum (the one where the seven wives each have seven sacks containing seven cats who each have seven kits, and you have to figure out how many are going to St. Ives) has a decidedly archaic antecedent. An Egyptian document more than 3,600 years old, the Rhind Mathematical Papyrus, contains a puzzle of sevens that bears...