Why do some people get confused on LCM and GCF?

Answer 1

Perhaps the C in both means confusion! To eliminate the confusion let's look at some of the reasons for this confusion. Both LCM and GCF have a lot in common. When there are many similarities, it is difficult to see the differences. Both the LCM and GCF are used when studying fractions, a scary topic in and of itself, and both have the word "common" in them when the acronym is read as words. The most confusing part, however, is when looking for the factors, which is a smaller number, we say the word, "greatest" first! When looking for the multiples, which will be a larger number, we say the word, "least" first! I teach my students to say, "Factor, Greatest common factor!" as well as, "Multiple, Least common multiple!" I hope this helped someone! email me: pshaffer@bethsd.org Mrs. Pam Shaffer "Hop2Math"

Answer 2

The greatest common multiple is infinite, and unnecessary for adding fractions etc