Start by setting up a factor tree for each number.
Factor in anyway that you'd like.
At the end, circle all prime numbers.
Remember, prime numbers are numbers
with only 2 factors, 1 and the number itself.
Now write these factors in least to greatest
multiplying them separate rows.
Circle factors they have in common.
Since 3 pairs of two's match up, multiply by 2 three times to get 8.
So the GCF is 8.
