Greatest Common Factor Calculator / Converter
E-mail This Page To A Friend Show
You have reached us maybe looking for answers to the questions like: What is the greatest common factor of 12 and 20? or what is the highest common factor (HCF) of 12 and 20? What is the GCF of 12 and 20?The first step to find the gcf of 12 and 20 is to list the factors of each number. The factors of 12 are 1, 2, 3, 4, 6 and 12. The factors of 20 are 1, 2, 4, 5, 10 and 20. So, the Greatest Common Factor for these numbers is 4 because it divides all them without a remainder. Read more about Common Factors below. See also:
The first step is to find all divisors of each number. For instance, let us find the gcf(12, 20). In this case we have:
The second step is to analyze which are the common divisors. It is not difficult to see that the 'Greatest Common Factor' or 'Divisor' for 12 and 20 is 4. The GCF is the largest common positive integer that divides all the numbers (12, 20) without a remainder. In the name greatest common divisor, the adjective "greatest" may be replaced by "highest", and the word "divisor" may be replaced by "factor", so that other names include highest common factor (hcf), greatest common measure, among others. So, the GCF is also known as:
Please link to this page! Just right click on the above image, choose copy link address, then past it in your HTML.
While every effort is made to ensure the accuracy of the information provided on this website, neither this website nor its authors are responsible for any errors or omissions. Therefore, the contents of this site are not suitable for any use involving risk to health, finances or property.
Calculate GCF, GCD and HCF of a set of two or more numbers and see the work using factorization. Enter 2 or more whole numbers separated by commas or spaces. The Greatest Common Factor Calculator solution also works as a solution for finding:
What is the Greatest Common Factor?The greatest common factor (GCF or GCD or HCF) of a set of whole numbers is the largest positive integer that divides evenly into all numbers with zero remainder. For example, for the set of numbers 18, 30 and 42 the GCF = 6. Greatest Common Factor of 0Any non zero whole number times 0 equals 0 so it is true that every non zero whole number is a factor of 0. k × 0 = 0 so, 0 ÷ k = 0 for any whole number k. For example, 5 × 0 = 0 so it is true that 0 ÷ 5 = 0. In this example, 5 and 0 are factors of 0. GCF(5,0) = 5 and more generally GCF(k,0) = k for any whole number k. However, GCF(0, 0) is undefined. How to Find the Greatest Common Factor (GCF)There are several ways to find the greatest common factor of numbers. The most efficient method you use depends on how many numbers you have, how large they are and what you will do with the result. FactoringTo find the GCF by factoring, list out all of the factors of each number or find them with a Factors Calculator. The whole number factors are numbers that divide evenly into the number with zero remainder. Given the list of common factors for each number, the GCF is the largest number common to each list.
Prime FactorizationTo find the GCF by prime factorization, list out all of the prime factors of each number or find them with a Prime Factors Calculator. List the prime factors that are common to each of the original numbers. Include the highest number of occurrences of each prime factor that is common to each original number. Multiply these together to get the GCF. You will see that as numbers get larger the prime factorization method may be easier than straight factoring.
Euclid's AlgorithmWhat do you do if you want to find the GCF of more than two very large numbers such as 182664, 154875 and 137688? It's easy if you have a Factoring Calculator or a Prime Factorization Calculator or even the GCF calculator shown above. But if you need to do the factorization by hand it will be a lot of work. How to Find the GCF Using Euclid's Algorithm
For additional information see our Euclid's Algorithm Calculator.
References[1] Zwillinger, D. (Ed.). CRC Standard Mathematical Tables and Formulae, 31st Edition. New York, NY: CRC Press, 2003 p. 101. [2] Weisstein, Eric W. "Greatest Common Divisor." From MathWorld--A Wolfram Web Resource. Help With Fractions: Finding the Greatest Common Factor. Wikipedia: Euclidean Algorithm.
Are you on the hunt for the GCF of 12 and 20? Since you're on this page I'd guess so! In this quick guide, we'll walk you through how to calculate the greatest common factor for any numbers you need to check. Let's jump in!
Want to quickly learn or show students how to find the GCF of two or more numbers? Play this very quick and fun video now! First off, if you're in a rush, here's the answer to the question "what is the GCF of 12 and 20?": GCF of 12 and 20 = 4 What is the Greatest Common Factor?Put simply, the GCF of a set of whole numbers is the largest positive integer (i.e whole number and not a decimal) that divides evenly into all of the numbers in the set. It's also commonly known as:
There are a number of different ways to calculate the GCF of a set of numbers depending how many numbers you have and how large they are. For smaller numbers you can simply look at the factors or multiples for each number and find the greatest common multiple of them. For 12 and 20 those factors look like this:
As you can see when you list out the factors of each number, 4 is the greatest number that 12 and 20 divides into. Prime FactorsAs the numbers get larger, or you want to compare multiple numbers at the same time to find the GCF, you can see how listing out all of the factors would become too much. To fix this, you can use prime factors. List out all of the prime factors for each number:
Now that we have the list of prime factors, we need to find any which are common for each number. Looking at the occurences of common prime factors in 12 and 20 we can see that the commonly occuring prime factors are 2 and 2. To calculate the prime factor, we multiply these numbers together: GCF = 2 x 2 = 4 Find the GCF Using Euclid's AlgorithmThe final method for calculating the GCF of 12 and 20 is to use Euclid's algorithm. This is a more complicated way of calculating the greatest common factor and is really only used by GCD calculators. If you want to learn more about the algorithm and perhaps try it yourself, take a look at the Wikipedia page. Hopefully you've learned a little math today and understand how to calculate the GCD of numbers. Grab a pencil and paper and give it a try for yourself. (or just use our GCD calculator - we won't tell anyone!) Cite, Link, or Reference This PageIf you found this content useful in your research, please do us a great favor and use the tool below to make sure you properly reference us wherever you use it. We really appreciate your support!
|