How much do you know about the world? Hans Rosling, with his famous charts of global population, health, and income data (and an extra-extra-long pointer), demonstrates that you have a high statistical chance of being quite wrong about what you think you know. Play along with his audience quiz — then, from Hans’ son Ola, learn 4 ways to quickly get less ignorant.

TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment, and Design – plus science, business, global issues, the arts, and much more.