Can you solve the Leonardo da Vinci riddle?
4,004,393 views | Tanya Khovanova • TED-Ed
You've found Leonardo da Vinci's secret vault, secured by a series of combination locks. Fortunately, your treasure map has three codes: 1210, 3211000, and... hmm. The last one appears to be missing. Can you figure out the last number and open the vault? Tanya Khovanova shows how. [TED-Ed Animation by Artrake Studio].