Is the greatest factor that two or more numbers have in common. One way to find the GCF is to make lists of the factors for two numbers and then choose the greatest factor that the two factors have in common.
5
Should be your answer
Good luck
Welcome to the factorial world :) Remember the Exclamation Point ( ! ) on the calculator, that is called factorial.
For instance: 1! = 1
2! = 1 x 2
3! = 1 x 2 x 3
and so on
10! = 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9 x 10 = 3628800
Crazy enough, 0! is actually equal to 1, try that on your calculator XD
Number 21 would be 6 39/40
