where is the factoral symbol

I assume you mean factorial... the symbol is "!"

n! = n! * (n - 1)! * (n-2)! ... * 1

For example

5! = 5 * 4 * 3 * 2 * 1 = 120 

It is the shift key and 1.

Just type   " ! "   after your number and enter......the calculator recognizes this symbol