Question

Okay, here is the officially dumbest question I will ever ask... Can someone help me remember GCF and LCM basics... Oh boy, I feel dumb... :/

Answer 1

How many times the largest number appears in a number = GCF , as LCM is the opposite and you must find the least times that number appears.

Answer 2

With exception of division... sorry for my translation. Maybe a more experienced person will write an answer more understandable.

Answer 3

Pick a couple of numbers and I'll give an example of how I find the LCM.

Answer 4

GCF: take each number and break it down into factors, find largest number they have in common
\[15 = 5*3\]
\[25 = 5*5\]
largest number in common is 5, so GCF of 15 and 25 is 5
LCM: take multiples of each number, find the smallest multiple they all have in common
\[6 \rightarrow 6,12,18,24...\]
\[8 \rightarrow 8,16,24,32...\]
smallest multiple is 24, LCM of 6 and 8 is 24

Answer 5

The LCM and the GCF for two numbers are related.

\[\large LCM(a,b) = \frac{|a\cdot b|}{GCF(a,b)}\]

Answer 6

Okay... ThanKS!!!

Answer 7

There's another interesting way to find the GCF of two numbers:
http://en.wikipedia.org/wiki/Euclidean_algorithm