GCF factor them and find the group of factors common to both example 18 and 24 18=2*3*3 24=2*2*2*3 common group is 2*3 or 6 gcf=6
LCM=least common multiupule means smallest number that both can go into evenly factor them and make a group that includes both of them, if you have repeats, replace them 18 and 24 18=2*3*3 24=2*2*2*3 LCM=2*2*2*3*3=72
