Question 666676
If your calculator has a ! button, it's usually under the probability section.

If you just have a four function calculator then n! = n*(n-1)*(n-2)...*1

So, we can evaluate 12! as:

12*11*10*9*8*7*6*5*4*3*2*1

and 8! = 8*7*6*5*4*3*2*1

Then you see that we can cancel out 8*7*6*5*4*3*2*1 to get

12*11*10*9 =  11880