Question 6397
The LCM of two numbers is the smallest number that is a multiple of both of these numbers.  For example, given the numbers 6 and 12, the smallest (least) number that both 6 and 12 divide into would be 12.  In addition to 12, you can see that 24, 36, 48, etc. would all be multiples of both 6 and 12 since both 6 and 12 divide evenly into all of these numbers.  However, the SMALLEST number that you can find that is evenly divisible by both 6 and 12 is 12.


As a second example, given 3 and 8, the LCM would be 24, since 24 is a multiple of both 3 and 8, and there is no smaller number that does this.  


Sometimes the LCM is the larger of the numbers like for 6 and 12.  Sometimes the LCM is the product of the numbers.  Sometimes you have to take multiples of the larger number until you find the number that works.  For example, given the numbers 9 and 12, to find the LCM, take multiples of 12 (like 12, 24, 36, etc.) until you find one that is divisible by 9.  The first one in this list is 36 so the LCM is 36.  


One of the main reasons for finding the LCM is because the LCM is the Least Common Denominator that you need when adding two fractions.


I have a section in my book Basic Algebra: One Step at a Time that might be helpful.  You can find it on my website by clicking on this URL.  Someday I might make it a lesson for this website.  Until then, at least you can have it here:


http://www2.scc-fl.edu/rrapalje/BasicAlgebra/Samples%20from%20Basic%20One%20Step%20Ch%203/3.03%20LCD/3.03%20LCD.htm


R^2 at SCC