Contributed by
Vijay Fafat
This story reminded me of Feynman's question: if there is one single sentence you could pass on to postholocaust survivors, what would it be? ("The world is made of atoms" was his answer. For Math, a single sentence might be difficult but would we select a pithy paragraph about Calculus? complex numbers? consistency of diffferent types of geometries? ). It was figuratively reminiscent of a story by Frederic Brown, I think, which effectively captured the idea that even if you found a time traveller from some distant future, it might not help you advance your technology since the average person is quite ignorant of most of the stuff around him/her so that the visitor from the future would have no idea how his time machine or the various gizmos of his era functioned.
So there is this massive atomic war which leaves just a few humans and their mutant children around and they decide to salvage as much of their knowledge as
possible. Of course, since they recall only rudimentary fragments of knowledge like most common men do, they make a mess of creating this knowledgebase through funny Chinese whisper. As they discuss mathematics, one of them recalls the Pythagorean theorem as follows:
(quoted from PostBombum [aka PostBoomboom])
"Who knows something about Geometry?"
"The Pythagorean Theorem", said Silva, whose one eye now shone with energy.
"What's that?"
"It's a way to measure the sides of a triangle. Listen, it goes more or less like this: the sum of the sides is equal to the hypotenuse.". He took a knife and drew a right triangle on the ground. "You see? It means this side is equal to the sum of these other two"
"But those aren't the same!"
"Apparently, no, but mathematically, yes". That's why Pythagoras had to prove it"

It quite encapsulated for me the general feeling students have when they don't understand a proof  "this makes no sense so it is not really true, it is just a mathematical proof."
The story ends with a nice example of Richard Guy's law of small numbers:
(quoted from PostBombum [aka PostBoomboom])
The square of two is four. Therefore, in order to find the square of a number, multiply it by two. For example, the square of 8 is 16, of 12 is 24, of 24 is 48...."

