Enjoy these fun facts from The Calculator Site:
You multiply Pi multiplied by the radius squared to find the area and multiply area by height to find the volume, That means the volume of a pizza that has a nominal radius of (z) and height (a) will, of course, be: Pi × z × z × a
And strangely, if you enter Pi to two decimal places (3.14) in the your calculator and look at it in the mirror, you'll see it spells 'pie'.
The spiral shapes of sunflowers and other patterns in nature follow a Fibonacci sequence, where adding the two preceding numbers in the sequence gives you the next (1, 1, 2, 3, 5, 8, etc.)
It only takes 23 people to enter a room to give you an evens chance that two of them have the same birthday. With 75 people in the room the chances rise to 99 per cent!
If you multiply 111,111,111 × 111,111,111 you get 12,345,678,987,654,321 - a palindrome number that reads the same forwards or backwards. And that works all the way back down to 11 x 11 (121) or just 1 x 1 (1).
A googolplex is 10 to the power of a googol, or 10 to the power of 10 to the power of 100. Our known universe doesn't have enough space to actually write that out on paper. If you try to do that sum on a computer, you'll never get the answer, because it won't have enough memory.