View the full lesson here: http://ed.ted.com/lessons/michael-mitchell-a-clever-way-to-estimate-enormous-numbers

Have you ever tried to guess how many pieces of candy there are in a jar? Or tackled a mindbender like: “How many piano tuners are there in Chicago?” Physicist Enrico Fermi was very good at problems like these — learn how he used the power of 10 to make amazingly fast estimations of big numbers.