# How To Fold Things Into Thirds, Sevenths, and Thirty-Sevenths: A Journey Into Primes, Binary-Decimals, and More!Master ClassVirtual

Tuesday, Feb 15, 2022Thursday, Feb 17, 2022Friday, Feb 18, 2022

4:00 p.m. – 5:30 p.m. EST

Folding paper into halves, quarters, or eighths by hand is straightforward enough. It doesn’t seem as easy, though, to fold something into odd fractional amounts, such as thirds or thirteenths with the same degree of accuracy. Yet surprisingly, there is a natural technique for doing so, based on the simple act of folding lengths in half. This solution suggests that there’s a curious interplay between the powers of two (arising from repeated folding) and odd fractional amounts—an interplay that we can both describe mathematically and see in front of us. But watch out! At the heart of this lurks questions that are easy to ask, but whose answers are not currently known. We’ll start by playing with folding (bring along something to fold, like a tie!), and then encounter a 100-year-old unsolved mystery. We’ll use the simple act of folding to bring us to the edge of known mathematics, and let discoveries unfold—ha!—right before our eyes.

This is a three-session master class. In the first two sessions, teachers learn from the master. In the third, participants have a rare and valuable opportunity to exchange ideas with other brilliant teachers. Participants are assigned a small amount of homework to prepare for each session.

## James Tanton, Global Math Project

Dr. James Tanton earned his PhD in mathematics from Princeton University. He is an author, a consultant, and ambassador for the Mathematical Association of America; chair of the Advisory Council for the National Museum of Mathematics; and a founder of the Global Math Project, an initiative to transform the entire world’s perception of what mathematics can, and should, be. Tanton has taught mathematics both at university and high school institutions. He advises on curriculum, consults with teachers, and gives demonstration classes, lectures, and professional development sessions across the globe. He is also a recipient of a Joint Policy Board for Mathematics Communication Award.