Finding the greatest common factor

1. FINDING THE
GREATEST
COMMON
FACTOR

2. What are factors?
Factors are the numbers multiplied to get the
product.
Example:
the factors of 12 are ; 1, 2, 3, 4, 6, 12
- 4 and 3
- 6 and 2
- 12 and 1

3. Common factors are those numbers that are factors of
both numbers.
Example:
12 : 1, 2, 3, 4, 6, 12
16 : 1, 2, 4, 8, 16
The common factors are 1 , 2 and 4.
What are common
factors?

4. Greatest Common Factor or GCF is the largest of the common
factors.
Example:
12 : 1, 2, 3, 4, 6, 12
16 : 1, 2, 4, 8, 16
The common factors are 1 , 2 and 4.
The greatest common factor is 4.
What is greatest common
factor?

5. WAYS TO FIND GREATEST
COMMON FACTOR
1. Listing Method
In this method you are going to write down all the factors of the two numbers and identify the
greatest common factor.
Example:
36: 1, 2, 3, 4, 6, 9, 12, 18, 36
56: 1, 2, 4, 7, 8, 14, 28, 56
Common factors: 1, 2, 4
GCF: 4

6. 2. Factor Tree
In this method get the prime factorization of both numbers.
36: 2 x 2 x 3 x 3
56: 2 x 2 x 2 x 7

7. 3. Continuous Division
In this method you are going to divide until there is no more
common on both numbers.