Need a laugh. Any good maths jokes?
There was an expert accountant who was well versed in game theory. He heard that his intelligent niece, who was five years old, always took a 50p piece, when a choice between a 50p piece and a pound coin was offered to her.
He went to see his niece and offered her just such a choice. She took the 50p and said
"Thank you Uncle".
The accountant tried to explain to his niece
"You must understand, a pound coin is twice as valuable as a 50p piece, so you should always choose the pound coin."
The niece replied
"Uncle, but then people will not offer me any money."
. . $\displaystyle \begin{array}{c}\text{What is the difference between} \\ \text{a }psychotic\text{ and a }neurotic? \\ \\ \text{A psychotic thinks }2 + 2 \,=\,5. \\ \\ \text{A neurotic knows that }2 + 2 \,=\,4 \\ \text{but it worries him.} \end{array}$
. . $\displaystyle \begin{array}{c}\text{What is the difference between} \\ data\text{ and }in\!f\!ormation? \\ \\ \text{382436: data} \\ \\ \text{38-24-36: information} \end{array}$
This reminds me a quote from the article "On the Essence of Mathematical Proofs" from the book "A Stress Analysis of a Strapless Evening Gown" (1963) (double translation to and from Russian).
Relying on mathematical proofs, scientists managed to unite previously disconnected areas, thermodynamics and communication technology, into a new discipline: information theory. "Information," defined scientifically, is proportional to surprise: the more surprising the message, the more information it contains. If, having lifted a receiver, a man hears "Hello," this will not surprise him very much; there will be considerably more information if instead of "Hello" he gets an electric shock.