Why don't perpetual motion machines ever work? - Netta Schramm Where do math symbols come from? - John David Walters What's the fastest way to alphabetize your bookshelf? - Chand John Why do airlines sell too many tickets? - Nina Klietsch What's the difference between accuracy and precision? - Matt Anticole How high can you count on your fingers? (Spoiler: much higher than 10) - James Tanton The unexpected math behind Van Gogh's "Starry Night" - Natalya St. Clair The Infinite Hotel Paradox - Jeff Dekofsky Why do competitors open their stores next to one another? - Jac de Haan Exponential growth: How folding paper can get you to the Moon Exploring other dimensions - Alex Rosenthal and George Zaidan Why do honeybees love hexagons? - Zack Patterson and Andy Peterson What is Zeno's Dichotomy Paradox? - Colm Kelleher The mathematical secrets of Pascal’s triangle - Wajdi Mohamed Ratemi Is math discovered or invented? - Jeff Dekofsky Group theory 101: How to play a Rubik’s Cube like a piano - Michael Staff How to defeat a dragon with math - Garth Sundem Check your intuition: The birthday problem - David Knuffke One is one ... or is it? The last banana: A thought experiment in probability - Leonardo Barichello How many ways can you arrange a deck of cards? - Yannay Khaikin Inside OKCupid: The math of online dating - Christian Rudder What's an algorithm? - David J. Malan A brief history of banned numbers - Alessandra King The math behind Michael Jordan’s legendary hang time - Andy Peterson and Zack Patterson The origin of countless conspiracy theories - PatrickJMT How many ways are there to prove the Pythagorean theorem? - Betty Fei The infinite life of pi - Reynaldo Lopes How to spot a misleading graph - Lea Gaslowitz A clever way to estimate enormous numbers - Michael Mitchell Why do people get so anxious about math? - Orly Rubinsten The case of the missing fractals - Alex Rosenthal and George Zaidan What happens if you guess - Leigh Nataro Making sense of irrational numbers - Ganesh Pai How the Königsberg bridge problem changed mathematics - Dan Van der Vieren Pizza physics (New York-style) - Colm Kelleher Did Shakespeare write his plays? - Natalya St. Clair and Aaron Williams The mathematics of sidewalk illusions - Fumiko Futamura Why are manhole covers round? - Marc Chamberland Can you find the next number in this sequence? - Alex Gendler What is a vector? - David Huynh A brief history of numerical systems - Alessandra King The coin flip conundrum - Po-Shen Loh The mighty mathematics of the lever - Andy Peterson and Zack Patterson What in the world is topological quantum matter? - Fan Zhang An introduction to mathematical theorems - Scott Kennedy How to visualize one part per million - Kim Preshoff + The TED-Ed Community How does math guide our ships at sea? - George Christoph How to organize, add and multiply matrices - Bill Shillito The time value of money - German Nande Why don't perpetual motion machines ever work? - Netta Schramm Where do math symbols come from? - John David Walters What's the fastest way to alphabetize your bookshelf? - Chand John Why do airlines sell too many tickets? - Nina Klietsch What's the difference between accuracy and precision? - Matt Anticole How high can you count on your fingers? (Spoiler: much higher than 10) - James Tanton The unexpected math behind Van Gogh's "Starry Night" - Natalya St. Clair The Infinite Hotel Paradox - Jeff Dekofsky Why do competitors open their stores next to one another? - Jac de Haan Exponential growth: How folding paper can get you to the Moon