The number N = 69,720,375,229,712,477,164,533,808,935,312,303,556,800 is special - it is the smallest number that has all numbers 1 to 100 as factors. The puzzle: what is the prime factorization of N? Watch the video for a solution....

This puzzle went viral in the discrete mathematics community because so many people got it wrong! You roll a fair dice until you get a 6. What is the expected number of rolls, including the roll of 6, conditioned on the event that all...

The card game of memory (aka concentration) is a children's game to test visual recall. Strategically you can figure out the best move by doing probability calculations. This video explains the best possible way to play the game...

You are given a list of 5 mathematicians and have to match each to the correct birth year. But since you were never taught about these mathematicians, you do not know any of the answers. So you decide to guess randomly by matching the 5...

You have a full 12 liter jug and empty 5 and 8 liter jugs. Can you measure exactly 6 liters? This problem dates to 1484 and was posed in the context of a milkman making a home delivery to a customer. The story goes this riddle so...

A servant has a method to steal wine. He removes 3 cups from a barrel of wine and replaces it with 3 cups of water. The next day he wants more wine, so he does the same thing: he removes 3 cups from the same barrel (now with diluted...

Thanks to Tim for sending this problem! The total amount of sand contained in Boxes A, B and C is 360 grams. First a mathematician pours 1/6 of the sand from Box A into Box B. After that, the mathematician pours 1/3 of the sand in Box B...

The sequence of numbers 1, 1, 2, 3, 5, 8, 13, etc was described by Fibonacci around 1200 AD. The Indian mathematician Pingala found the sequence at least 1,000 years before (probably 200 BC) while analyzing Sanskrit poetry. This video...

This is one of those brain teasers that sounds like it's impossible to solve but you can work through it (like the logic puzzle of Cheryl's birthday). A mathematician tells a census taker he has 3 children. The product of their ages is...

This video includes 3 puzzles that ghosts are useful mathematically. Can you figure them out? Puzzle 1: A father left 17 goats to his three sons. His will promised 1/2 of the goats to the oldest son, 1/3 to the middle son, and 1/9 to the...

It's the final play of the 1787 World Math Championships. The talented 10-year old Gauss faces a challenging question from his math teacher. Will the young student show up his teacher, or does he still have lessons to learn? I wanted to...

If the last digit of this POSITIVE whole number becomes the first digit, the resulting number is exactly twice as large. My number is the smallest whole number with this property. What is my number? Watch the video for a solution. I'll...

15-year old Joseph Rosenfeld thought he spotted an error in the Boston Museum of Science. The exhibit Mathematica has a sign that says the golden ratio is (√5 - 1)/2. He remembered and checked online that the golden ratio is supposed to...

Mathematician Ed Southall, from the University of Huddersfield, created a stir when he tweeted this problem (@solvemymaths). The problem was covered in "The Daily Mail" and "The Sun." In this video I present one way to solve it. My blog...

The numbers "infinity plus 1" and "infinity squared" sound like they are made up, but mathematicians do use such numbers in set theory. They are called transfinite ordinals and they arise in combinatorial game theory. This video...

This problem caused an uproar on social media because it was too hard, and it brought some Scottish students to tears (it gave many mathematicians crocodile tears...sorry I couldn't resist). Can you figure it out? A crocodile preys on a...

A fly, moving at 40 mph, zigzags back and forth between two trains, each moving at 20 mph. If the trains are 100 miles apart initially, how much distance will the fly travel? The genius mathematician John von Neumann was able to solve...

The Indian mathematician Dattaraya Ramchandra Kaprekar discovered the number 6174 is reached after repeatedly subtracting the smallest number from the largest number that can be formed from any four digits not all the same. The number...

Strip away the trimmings of a traditional science presentation, add cocktails, and you have WSF Spotlight. Here, astrophysicist Mario Livio, from the Hubble Space Telescope Science Institute, takes us on a tour of the cosmos in all its...

And it could swing the 2024 elections. Subscribe and turn on notifications 🔔 so you don't miss any videosf='http://goo.gl/0bsAjO' target='_blank' rel='nofollow'>videos In 2013, a divided Supreme Court gutted one of the major pillars...

Reader’s Digest has called “Mathemagician” Arthur Benjamin “America’s Best Math Whiz.” Returning in an encore presentation, Arthur Benjamin displays feats of mental mathematical gymnastics and shares the secrets behind his skills. A...

Extra dimensions of space—the idea that we are immersed in hyperspace—may be key to explaining the fundamental nature of the universe. Relativity introduced time as the fourth dimension, and Einstein’s subsequent work envisioned more...

In this highly entertaining performance combining math with magic, Arthur Benjamin—aka, the the "Mathemagician"—displays amazing feats of mental mathematical gymnastics and explains the secrets behind his lightning-fast math skills. How...