Finding the Greatest Common Factor (GCF)


Before we go into great detail on how to factor by the GCF, I like to spend an entire lesson teaching students how to find the GCF. I understand this is typically a concept covered in 6th grade, but I still like to complete a little refresher to make sure students have a good understanding of the topic.


First, we begin by completing a set of notes on the concept. I have a set of digital notes available where we use various methods to help determine the GCF. Popular methods for finding the GCF include the upside-down cake method, factor trees, prime factorization, listing the factors, etc. I typically like to use the upside-down cake method the most, but I give students the option to use whatever method makes the most sense to them. The digital notes I have available include both finding and factoring by the GCF. Click on the image to view more information on the resource.


After completing the notes, I have students complete a click and drag activity on finding the GCF. This activity includes several different expressions where students need to determine both the numeric and algebraic GCF. Once they have determined their answer, they will look for it on the bottom of the slide. They will click and drag their answer to match the expression at the top. This activity is available, for free, click the image to access.