maths+facts

**Interesting (Probably) Mathematical Facts**
Any quadrilateral will tessellate

math 666=6+6+6+6^3+6^3+6^3 math

math 169=13^2\, and\,\, 961=31^2 math

There is only one number that obeys the following rules it uses each digit 1-9 once only the first digit is divisible by one (really!!!) the first two digits make a number divisible by 2 The first three digits make a number divisible by 3 and so on to all nine digits CAN YOU FIND IT P.S. This is called a delectable number (according to mr Francombe anyway)

1 is triangle and square, so is 36, then you have to wait till 1225 and 41616

A piece of paper can be folded in half about seven times as any more and the paper starts to tear. If we could fold it 50 times however the thickness would be the distance from the earth to the sun

If a number is divisible by three then the sum of its digits is also divisible by three

In the infinite string of digits that is PI, at position 763 there are six nines in a row. (**Lookup** - Feynman Point)

A4 Paper is such that, if the diagonal of the square is measured it is the same length as the length of the paper This means you can calculate the ratio of the length of the sides of A4 (and A5, A3 etc.)

math 2^{13,366,917} \,-1 math the largest known prime number from 2001 math 2^{32,582,657} \,-1 math is the largest known prime number at this time (discovered 2006)

They are discovering about 1 new prime number every year. [|Here] is the biggest, i would put it here but its would not fit.

math A \, Googol=10^{100} math math A\, Googolplex=10^{googol} math How many zeros has a Googolplex?

In a room full of 23 people, there is a 50% chance that two people have the same birthday (**Lookup** - The Birthday Problem)

There is a number where all the letters are in alphabetical order too. I will leave that one for you to find. Also see **discussion board** for a challenge.
 * FOUR** is the only number that describes the number of letters it has. (actually that one is a bit rubbish)

Any map can be coloured in such a way that no two connecting regions have the same colour. Whats amazing is it only needs 4 different colours. (**Lookup** - Four colour problem)

math 1^3+2^3+....+n^3=(1+2+....+n)^2 math so for example math 1^3+2^3+3^3+4^3=(1+2+3+4)^2=100 math (**Lookup** - Multiplicative Functions)

math \frac{\pi}{2}=\frac{(2 \times 2) \times (3 \times 3) \times (4\times 4)}{(1 \times 3) \times (3 \times 5) \times (5\times 7)} math also, by removing every other term we can get. math \sqrt{2}=\frac{(2 \times 2) \times (6 \times 6) \times (10\times 10)}{(1 \times 3) \times (5 \times 7) \times (9\times 11)} math (**Lookup** - Wallis formula)