f)+LCM+&+GCF

What are the definitions of LCM & GCF? Posted by: **DummyDerrick** LCM = Lowest Common Multiple, and GCF = Greatest Common Factor

Posted by: Craxyjosh LCM = Lowest common Multiple and GCF = Greatest Common Factor What is a factor? Posted by: **DummyDerrick**

A number that you multiply together to get a different number, for example, 3 and 4 are factors of 12 because 3x4=12

What is a multiple? Posted by: **DummyDerrick**

A multiple is a continuous number line that has a pattern, for example, the multiples of 3 are 6,9,12,15,18,21,24,27,30.....

How do you calculate LCM and GCF? (is there more than one way?) posted by: **smokey-dice1212**

Least Common Multiple: Find the least common multiple for 168 and 40: 1. Do a factor tree on each number. 168................................................... 40 2 x 84 ..........................................2 x 20 2 x 2 x 42............................... 2 x 2 x 10 2 x 2 x 6 x 7 ...................... **__2 x 2 x 2 x 5__** **__2 x 2 x 2 x 3 x 7__** 2. Match up all of the same numbers in the prime factorization. (The final row of numbers is your prime factorization) Any numbers that do not match you will leave off to the side. Example: 168 = 2 x 2 x 2 x 3 x 7 40 = 2 x 2 x 2 ...................... x 5 Since all of the twos match up, you use that combination only once. In essence, one set of twos cancels out the other. The three, seven and five do not match up, so you simply multiply them with the set of 3 twos you have. 2 x 2 x 2 x 3 x 7 x 5 = 840 840 is your Least Common Multiple (LCM)

Greatest Common Factor : Find the Greatest Common Factor for 168 and 40: 1. Do a factor tree on each number. 168 ........................................40 2 x 84 ...............................2 x 20 2 x 2 x 42 ....................2 x 2 x 10 2 x 2 x 6 x 7............ **__2 x 2 x 2 x 5__** **__2 x 2 x 2 x 3 x 7__**

2. Circle ONLY the matching numbers in each prime factorization. (The final row of numbers is your prime factorization) Example: 168 = 2 x 2 x 2 x 3 x 7 40 = 2 x 2 x 2 ....................... x 5 3. Multiply ONLY the numbers that match up. 2 x 2 x 2 = 8 8 is your Greatest Common Factor (GCF)

_ __Posted by: **smokey-dice1212**__

An even easier way to finding LCM is to write the multiples of the numbers down until you find a matching number from all multiples.

For example:

If you want to find the LCM for 4 and 9, this is what you do :

Write out the multiples:

4, 8, 12, 16, 20, 24, 28, 32, __36__, 40, 44, 48

9,18, 27, __36__, 45, 54, 63, 72, 81,

and then find the first number that matches in both multiples, in this case, 36 is the LCM for 4 and 9.

Posted by: **CoconutCracker** Way 1 The Indian Way: Ex: 2) __24 18__ 3) __12 9__ __4 3__

GCF= 2 x 3 =6 LCM= 2 x 3 x 4 x 3

Way 2 The Venn Diagram: Ex: http://www.youtube.com/watch?v=3S1GbIlmUPo&feature=related is the video for you. it teaches the Venn Diagram way very clearly.

Way 3 Factor Tree : Ex: http://www.youtube.com/watch?v=lAwq8hnVxY8&feature=related This is the video for you that teaches the factor way.

Way 4 Crazy Way To Find GCF: Ex: 2 __)36 42__ 3 __)18 21__ __6 7__ GCF=2x3=6 LCM=36X7=252 OR 42X6=252 Here you can learn abut other ways to learn your lowest common multiple and greatest common fraction.

by:bigbadbob12 Way 5 Birthday Cake Way: http://www.youtube.com/watch?v=8UYFltrQZBU&feature=related media type="youtube" key="8UYFltrQZBU" height="344" width="425"