Calculate the GCF of 9 and 30
The greatest common factor, sometimes also called the highest common factor of two positive integers is the largest divisor common to them
Answer: The GCF of 9 and 30 is 3
Let us see how to find the GCF of 9 and 30
We can find the GCF by the following two methods:
- By listing factors
- Long Division method
Method 1: By listing factors
- The factors of 9 and 30 will be listed
- The greatest common factor will be the GCF
Here are the factors of 9 and 30 listed
Factors of 9 = 1,3,9...
Factors of 30 = 1,2,3,5,6,10 ...
The greatest factor among them is 3
Thus, the GCF of 9 and 30 is 3
Method 2: Long Division method
Divide the larger number by the smaller one.
Then the remainder is treated as divisor and the divisor as dividend.
Divide the first divisor by the first remainder.
Divide the second divisor by the second remainder.
Continue this process till the remainder becomes 0.
The divisor which does not leave a remainder is the H.C.F. or G.C.F. of the two numbers and thus, the last divisor is the required greatest common factor (G.C.F) of the given numbers.