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Hand-picked explainers from mathematicians and science communicators. Videos load only when you press play, and play through YouTube's privacy-enhanced mode.
6174: the number every 4-digit number falls into
Take almost any four-digit number, sort its digits high-to-low and low-to-high, subtract, repeat. You always land on 6174 — Kaprekar's constant. Try it with 1522 in the decoder.
1729: the taxi-cab number
The smallest number that is the sum of two cubes in two different ways, and the story of Ramanujan spotting it from a taxi number.
Benford's law in the wild
Why leading digits in real data are skewed toward 1 — and how auditors use it to catch faked numbers. Read our guide.
Graham's number
A number so large that writing it in ordinary digits is impossible in the observable universe — explained with Ron Graham himself.
Infinity is bigger than you think
Countable and uncountable infinities, and Cantor's diagonal argument.
1 + 2 + 3 + … = −1/12?
One of the most argued-about maths videos online, and what that "sum" really means in physics and analysis.
The Banach–Tarski paradox
How one ball can, mathematically, become two identical balls — a deep dive into infinite sets.
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