What Does An Exclamation Point Mean In Math

What Does An Exclamation Point Mean In Math

The exclamation point means the factorial of a number. This is the product of natural numbers from 1 to the number itself.

3! = 1 · 2 · 3 = 6

6! = 1 · 2 · 3 · 4 · 5 · 6 = 720

The factorial is defined only for natural numbers and zero.

Please note that:

0! = 1 

1! = 1

And here some extra examples:

145 = 1! + 4! + 5! = 1 + 24 + 120 = 145

40 585 = 4! + 0! + 5! +8! + 5!