Figure: A classic problem in which the number e makes an appearance is calculating the number of ways you could distribute hats back at the end of a party such that no one gets their own hat. This is known as a derangement.
One of the reasons e is such a famous number is because it pops up everywhere-from calculating interest to determining population growth, from measuring radioactive decay to the normal distribution. It's frequently found in both applied mathematics and pure mathematics alike. Check out different applications and appearances of the number e using the menu above.
