Why aren’t left-handers extinct? What makes a rainbow round? How is a pancreas . . . like a pendulum? Publisher's note: It's a Numberful World was published in Australia under the title Woo's Wonderful World of Maths. These may not look like math questions, but they are—because they all have to do with patterns. And mathematics, at heart, is the study of patterns. That realization changed Eddie Woo’s life—by turning the “dry” subject he dreaded in high school into a boundless