From birth rates to how we perceive the passing of time, mathematical patterns shape our lives. But for those of us who left math behind in high school, the numbers and figures we encounter as we go about our days can leave us scratching our heads. In this accessible guide, Kit Yates takes a tour of everyday situations and grand-scale applications of mathematical concepts, including the numerical and statistical underpinnings of controversies over DNA testing, Ponzi schemes, viral marketing, and even historical events like the Chernobyl disaster and the Amanda Knox trial.