what is the biggest common factor between 18 and 24
Let's list the factors of both.
18: 1, 2, 3, 6, 9, 18
24: 1, 2, 3, 4, 6, 8, 12, 24
Which number is the highest in BOTH sets?
It would be 6!
The GCF (greatest common factor) is 6.
+1667 
