Strategies to memorize π sometimes rely on devising a sentence with words of representative lengths. Isaac Asimov offered this one: How I want a drink, alcoholic, of course, after the heavy lectures involving quantum mechanics! Count the letters in each word and you get 3.14159265358979. That’s not the best strategy, though: What shall we do about zero? And it’s hard to reel off the digits impressively for friends when you have to stop and count the letters in each word. Arthur Benjamin, a mathematician at Harvey Mudd College, suggests using a phonetic code instead: 1 = t or th or...