Understanding numbers is essential - but humans aren't built to understand them. Until very recently, most languages had no words for numbers greater than five - anything from six to infinity was known as "lots". While the numbers in our world have gotten increasingly complex, our brains are stuck in the past. How can we translate millions and billions and milliseconds and nanometers into things we can comprehend and use? A clear, practical, first-of-its-kind guide to communicating and understanding numbers and data.