How much is a zillion?

The English language isn't always so exact when it comes to being specific about numbers. It turns out that people love words that give a sense of size, but are vague about an actual number, terms like zillion and umpteenth. Helen Zaltzman is the presenter of the podcast 'The Allusionist' that looks at the way we use language. Tim Harford has been talking to her about what are called indefinite hyperbolic numbers.

First broadcast on More or Less, 17 September 2017.