In mathematics, an exclamation point (!) denotes the factorial operation. The factorial of a non-negative integer nnn, written as n!n!n!, is the product of all positive integers from 1 up to nnn. For example:

4!=4×3×2×1=244!=4\times 3\times 2\times 1=244!=4×3×2×1=24

By definition, 0!0!0! is equal to 1. Factorials are widely used in combinatorics, probability, and algebra to count permutations and arrangements

. In summary:

• n!n!n! means multiply all integers from 1 to nnn.
• 0!=10!=10!=1 by convention.
• Example: 5!=5×4×3×2×1=1205!=5\times 4\times 3\times 2\times 1=1205!=5×4×3×2×1=120.

This notation is distinct from the exclamation mark used in punctuation; in math, it specifically refers to this product operation