You can put this solution on YOUR website!
We know that n!=n*(n-1)*(n-2)*...*2*1
So we can expand
Now... looking at the expression above... can anything divide out (i.e. get rid of any number that appears in the numerator and denominator). This leaves:
Now this expression can be calculated as an integer on your calculator... I will leave that for you to do .
Obviously if we had large numbers... it wouldn't be a good idea to write out the whole factorial, but you may be able to see some patterns once you do some examples... (try to find them)
Hopefully this helps a bit... let me know if you are still unsure