Greatest Common Factor Examples

Worked examples of how to compute the greatest common factor...

You can use this web page to get worked examples of how to find the greatest common factor of two numbers - also called the greatet common divisor. The way it works is like this -

First, click the Generate Example button below. You'll see two numbers, and be asked for the greatest common factor.
Once you've found the greatest common factor, click Show Solution. Then you can see if you worked out the greatest common factor correctly.
Finally, click on Show Method to see the steps for solving the problem. There are two methods shown.
- One way to find the greatest common factor of two numbers is to find all the factors, identify the factors the two numbers have in common, and see which of these is the greatest. This is easy to understand, but (as it turns out) is not the quickest way.
- The other way (called Euler's method) is less intuitive, but works faster for large numbers.

Each example is randomly generated, so there's an infinite supply. Are you ready?