How do you figure out the lowest common factor?

Answer by  Joe12 (189)

First list all the factors that could be multiplied to equal the numbers in your set. If the numbers you have are 21 and 30, you would list 3x7 for 21 and 2x15 and 3x10 for 30. Now, pick the lowest number that occurs on both lists. In this case, the answer would be 3.

Answer by  amswplusone (652)

The lowest common factor is always 1. You might mean Greatest Common Factor, which you get by listing all smaller numbers that divide each of your numbers and choosing the largest one that appears in both lists. You might mean Least Common Multiple, where you list all mutiples of each number until you find the smallest one on both lists.