You've probably heard of the Pythagorean Theorem from 10th grade geometry class, but have you heard of Pythagoras' Constant? So, here's the skinny: Pythagoras' Constant is the square root of 2 (1.41). It's also the first irrational number ever discovered.

In Roman numerals, there are a total of zero zeros. While the ancient Greeks were aware of the idea of zero, they did not believe zero to be a number. For example, Aristotle determined that zero was not a number since it could not be divided by zero. To indicate the notion of zero, the Latin term "nulla" would have been used instead of a Roman numeral. There was no need for a numeral to symbolise zero, thus there was no need for one.

You've probably never considered it, but there is only one number that is spelt with the same amount of letters as itself. Can you figure out which one it is? No? It's 4 o'clock now. Oh, and a calculator's number 4 is made up of four light bars. Tell your friends about this at your next get-together! (However, you might not make many friends.)

A perfect number is a positive integer that is equal to the sum of its positive divisors in number theory. Six is the lowest perfect number, according to this criterion. If you scratched your brow and said, "Huh? The next perfect number is not until 28. It turns out that perfection is really rare...

Have you ever heard that the number 9 is said to be "magical"? No? It is, and here's why: if you multiply a number by 9 and put all of the digits of the new number together, the total will always equal 9.

The number 1 is frequently misidentified as a prime number. However, this is not the case—one does not meet the qualifications to be prime (being divisible by both 1 and itself). 1 divided by 1 equals...1. Nothing has been split.

Because the volume of a cylinder is PI times the radius squared times the height, a pizza with radius "Z" and height "A" has a volume of... PI * z * z * a.

A palindromic number is just a number that is the same reverse as it is forwards, for example, 23432.
So, if we multiply 1 by 1, we get 1. Okay, that was a lazy palindrome; let's move on.
11x11 = 121, 111x111 = 12321, 1111x1111 = 1234321, and so on.

Multiplying 111111111 by 111111111 yields 12345678987654321.
Furthermore, the two integers you are multiplying do not have to have the same amount of ones. For instance, 11x1111 = 12221 and

Various people have told me that this has been used as an interview question by many firms to assess "out-of-the-box thinking." The "secret" here is to think of a cake as a three-dimensional cylinder rather than a two-dimensional circle, as most people do. This enables us to not only perform vertical cuts, but also horizontal cuts. So, if you use two of your cuts to make a cross on the top of the cake, effectively dividing it into four equal parts, and your third cut as a horizontal cut across the centre of the cake, thereby dividing each of the four equal portions in half, you'll have eight equal pieces.