Factorial Notation . . . !
. . .
Shown and Explained
Background - why Factorial Notation symbols are used. . .
Symbols are a concise way of giving lengthy instructions related to
numbers and logic.
Symbols are an invention, not a discovery. They are a
communication tool. Symbols are used to eliminate
the need to write long, plain language instructions to describe
calculations and other processes.
The most valuable, most frequently used Math Symbols . . .
The most important, most frequently used Miscellaneous symbols
are listed below.
Symbol for a "Factorial" -
The "factorial of n" is the factorial of a positive integer called n. There are no factorials of negative integers.
The "factorial of n" is the product of n, and all the positive integers smaller than n.
The factorial function is written:
n! = n(n-1)(n-2)(n-3) . . . (1)
The factorial of zero is defined as 1.
0! = 1
Factorials are used to calculate:
1. The number of different ways the same items can be arranged (Permutations)
2. The number of different ways to combine groups of objects without regard to order (Combinations).
6! = (6)(5)(4)(3)(2)(1)
6! = 720