Transcript for NFL player turned math whiz John Urschel
NFL offensive lineman and a current phd candidate at M.I.T. That's right. I said it. He's also the author of this new book called "Mind and matter." Please welcome John urschel. John, welcome, man. Happy to be here. Looking at John is the reason -- see how big John is? That's why I retired. I couldn't handle that anymore, big guys like this. You co-wrote this book with your wife. How was it collaborating with your wife on this book? It was fantastic. She's an amazing writer, has written many great books and she really made me sound more eloquent than I really am. Those are the best kind of partners, aren't they? This is kind of equal parts math but also a memoir. So why is math so special to you? So, math is something that I've loved ever since I was very little. I loved puzzles. I loved problem solving. And math truly is just a set of tools to try to solve problems in this world. It's not always shown like that and people sometimes, you know, they get a certain feeling about math. They think they don't like it but perhaps it's often because it's been shown to them sort of the wrong way I think. Growing up, your parents made it interesting to you. They fostered your love of math. There's a story I read about your father getting you to a class. Yeah. So after 8th grade I had a free summer and my father, he was studying at the university of Buffalo, so he just let me, you know, use his credentials and audit calculus scores. Now you lost me. In 8th grade. Also, while you were playing at Penn state, you were teaching classes. Yeah, yeah. I got to teach two courses and I absolutely loved it. It was there that I really found out that teaching young people, inspiring young people in mathematics, this is a passion of mine. Aw, I love that. I love that. I love that. And to be able to put it into this book and kind of marry the two things that you love, I mean, math being one, football is the other. But you retired young. Yeah. What was the reasoning behind that? I came to love math more and more and more. By the time I got to M.I.T., it was hard for me to leave every spring. Wow. And focusing on my family, I now have a little one, I'm so excited to raise her and just to be able to teach her things as she grows older and older. I'll tell you one thing, we know she's going to love some math. She's going to have to. But you also have some math you want to show us. Yes, can I? We brought out our chalkboard. All: Math, math, math, math, math. I like it. I have a math magic trick for you. Okay, the math magic trick, okay. So what I'm going to do is I'm starting with the natural log of two which is equal to this infinite sum. All I'm going to do is move around some numbers and I'm going to end up with half of what I started with. Okay. So let me just rearrange this. What? I know, right? I'm going to start with one minus a half, minus a fourth, plus a third, minus a sixth, minus an eighth, plus a fifth, minus a tenth, minus a twelfth and here's where I need some math help. What's one minus a half? Half. Half. What's one-third minus a sixth? A third. One-third minus -- It's a sixth. We're okay. We're doing well. What's one-fifth minus a tenth? One-fifth. It's a tenth but that's -- Oh, my gosh, Rory, you're calling out the wrong answers. And now, we know we should always remove common denominators. We see there's a two in the denominator everywhere. When I take out one half, what do I get? One minus a half, plus a third, minus a fourth, plus a fifth. Is this looking familiar to anyone? This is what we have right here and what I have is one half of the natural log of two. Somehow I've just moved them around and I've got back to what I started with. You know what, I got another math trick for you guys. Let's see it. Now, you start with two but we're going to do something that gets it down to one. Okay, what is this? Two minus one. Yee! I like it. Amazing, amazing. Really is. John's book, "Mind and matter," is available right now. See if you can keep up.
This transcript has been automatically generated and may not be 100% accurate.