GCF

http://www.schooltube.com/video/0c162f9de8424b1eb155/Greatest-Common-Factor-GCF
 * // Definition: //**The GCF of numbers, or Greatest Common Factor is the largest factor shared between two or more numbers
 * // Summary: //**Greatest Common Factors can be used to reduce fractions.

**//How To://**


 * // Steps ://** There are 2 ways to find the GCF of 2 numbers

1. List all the factors of the your numbers. Circle the factors that are the same in both lists. Now, find the pair that has the greatest value, and that is your GCF. (This is may not be the best way since you could leave out factors.)

2. Take your numbers and create factor trees. Circle all your prime numbers. Then create a venn diagram. If your numbers have any prime factors in common, put them in the center of the diagram. All the others put on each side: One number's prime factors on one side, the other's on the other side. Now, multiply the numbers in the middle, and their is your GCF.

//**Easy Problems**// //Answer-4// //Answer-4// //Answer-5// what is the GCF of 10 ad 20 ? //answer-5//
 * What is the GCF of 4 and 8?
 * What is the GCF of 16 and 4?
 * What is the GCF of 25 and 30?

//Medium Problems// //Answer-6// What is the GCF of 4, 6, and 8? Answer: 2
 * What is the GCF of 12, 18, and 24?

What is the GCF of 9, 27, and 3 Answer: is three because you use 3 in 3x1 to get 3, 3x3 to get 9 and 3x9 to get the answer 27, so the factor 3 is the answer to this GCF problem How do you find the GCF for all the problems above? Answer: You can find the GCF for all the problems above by looking at the steps or looking down below: You can find GCF by listing all the factors that a number has up to itself then compare the two numbers factors and the greatest factor that is the same is your answer. Sometimes you need to find the GCF for more than just two numbers. And thats how you find GCF!
 * // Hard Problems //**

//**Pictures**// greatest common factor.online image. available [|www.illuminations.nctm.org]11/5/09


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