FINDING GCF
Greatest Common Factor
- is the largest number that is a common factor of two or more numbers
Greatest Common Factor
- is the largest number that is a common factor of two or more numbers
To find the greatest common factor:
- Determine if there is a common factor of the numbers.
- Divide both of the numbers by this common factor.
* If there are no common prime factors, the GCF is 1.
Example:
12m² + 6mn + 3n²
Step 1:
12m² = 3.2.2.m.m
6mn = 3.2.m.n
3n² = 3.n.n
(All have "3" in common)
GCF : 3
Step 2:
3 ( 4m² + 2mn + n² )
Usually you can find the Greatest Common Factor fairly easily by experimenting with possible divisors:
Start with the smaller number; it is the largest divisor of itself. Is it a divisor of the larger number? If so, you have the G.C.F.; if not: What is the next-largest divisor of the smaller number; is IT a divisor of the other number? Continue until you find a number that will divide into BOTH. Sometimes only the number '1' will work as a common divisor; for example: 21 and 16 have no common factor other than 1.
