what does this mean in math 10!? is it 10(9+8....) or 10)9x8...)?

Answer 1

! means factorial.

In mathematics, the factorial of a natural number n is the product of all positive integers less than or equal to n. This is written as n! and pronounced "n factorial" The notation n! was introduced by Christian Kramp in 1808.

Therefore 10! = 10x9x8x7x6x5x4x3x2x1 = 3 628 800