![Planet Money show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/026/080/small/npr-planet-money.jpg)
Summary: On the show today, the story of an innovation that changed the way the world works, and of the man who made this innovation possible. Luca Pacioli was a monk, a mathematician, a magician and possibly, the boyfriend of Leonardo da Vinci. Jane Gleeson-White, author of Double Entry: How the Merchants of Venice Created Modern Finance, tells us the story of Pacioli and how his book on mathematics changed business across the planet.