What is a Factorial?

What is a factorial? A factorial is a whole number which is found by multiplying all numbers down to 1. For example: If 8 is the given number (non-fractions) then the factorials are 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 40320. Basically you take the given number and multiple all the numbers between that number and 1 by each number. Using the above example: 8*7=56 *6=336 * 5 = 1680 * 4 = 6720 * 3 =20160 * 2 = 40320 * 1 = 40320. A factorial number is represented by an exclaimation mark next to it. 8! =40320; 5! = 120