Transcript of Faster than a Calculator by Mathemagician Arthur Benjamin at TEDxOxford conference.
Listen to the MP3 Audio here: MP3 – Faster than a calculator by Arthur Benjamin @ TEDxOxford
Well good afternoon, ladies and gentlemen. My name is Art Benjamin, and I am a mathemagician. What that means is, I combine my loves of math, or I should say maths and magic to do what I call “mathemagics.”
But before I get started, I’ve got a quick question for the audience. By any chance, did anyone – anyone here in the audience happen to bring with them this afternoon a calculator? If you have one, perhaps on your phone or somewhere and you are pretty comfortable using it, raise your hand. I will need a couple of people to help me out here. I see one, two and perhaps one more. Three, the three of you bring out your calculators and join me up here on stage and let’s give these volunteers a nice round of applause. Come on up!
Great. Over on this side please. Awesome. Now, since I have not had the chance to work with these calculators, I need to make sure that they are all working properly. Would somebody get us started by giving us a two-digit number, please? How about a two-digit number?
Oh, that’s fine. 74. And another – how about another two-digit number, how about on this side?
Multiply 74 times 39 on the calculator, make sure you get 2886, or the calculators are not working. Do each of you get 2886? Give them a round of applause.
Now I notice it took some of us a little bit of time to get the answer. That’s okay. I’ll give you a shortcut for multiplying even faster on the calculator. There is something called the square of a number, which most of you know is taking a number and multiplying it by itself. For instance, five squared would be? 25. Six squared would be 36. 73 squared would be something else, yeah.