The least common multiple is 330 and the GCF is 5. When you add numbers together to get 30 and 55 you keep multiplying until you get to a common number and the least common multiple is the first number you get that is the same in both. The GCF a number that goes into both of the numbers. There are online calculators that can get the LCM and the GCF for you. https://www.mathsisfun.com/greatest-common-factor-tool.htm (GCF calculator) https://www.mathsisfun.com/least-common-multiple-tool.html (LCM calculator)