PBS
Pbs: Greatest Common Factor
In this video, learn how to find the greatest common factor of two numbers. Then, see how this can be used to solve problems with large numbers. In the accompanying classroom activity, students learn to find prime factors using factor...
Calculator Soup
Calculator Soup: Greatest Common Factor Gcf Calculator
Calculate GCF, GCD, and HCF of a set of two or more numbers and see the work using factorization. An interactive calculator, explanations, and examples are included.
Cool Math
Coolmath: Gcf's and Lcm's Common Factors
These prealgebra-arithmetic lesson explains greatest common factors (GCF's)and shows how to find them.
Better Lesson
Better Lesson: Greatest Common Factor
Sixth graders will learn how to find the Greatest Common Factor of two or more numbers by using math manipulatives.
Amby Duncan-Carr
Amby Duncan Carr: Amby's Math Resources
Amby's Math Resources site is a tutorial that explains finding the greatest common factor. It also has examples that are done for you step by step, as well as examples for you to try (and check) on your own.
Khan Academy
Khan Academy: Greatest Common Factor
Find the greatest common factor of 2 or 3 integers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Wyzant
Wyzant: Factoring a Gcf From an Expression
The tutorial explains how to factor a greatest common factor from an expression. The resource includes a lesson with examples, practice problems, and an expression-factoring calculator.
Wyzant
Wyzant: Finding a Gcf
In this lesson from WyzAnt, students learn how to find the greatest common factor (GCF) for numbers and expressions. There are practice problems and a GCF calculator for assistance.
Wyzant
Wyzant: Factoring a Gcf From an Expression
This tutorial demonstrates how to factor the GCF out of a polynomial expression. An online worksheet is provided for extra practice.
Quia
Ixl Learning: Greatest Common Factor
Brush up on your math skills relating to the greatest common factor then try some practice problems to test your understanding.
Shmoop University
Shmoop: Basic Operations: Lcm & Gcf
Students learn about the least common multiple and the greatest common factor. The resource consists of notes, step-by-step examples, and practice problems with solutions.
Free Math Help
Free Math Help: Greatest Common Factor
The lesson investigates the greatest common factor. Explanations and sample exercises are provided.
Wyzant
Wyzant: Factoring a Gcf From an Expression
Students review factoring a greatest common factor from an expression. The handout consists of an example and answer sheet.
University of Waterloo (Canada)
University of Waterloo: Cemc: Math Circles: Number Theory Ii [Pdf]
This worksheet provides a series of problem-solving questions that require higher order thinking skills. Questions will include finding the greatest common divisor, and least common multiple.
Other
Greatest Common Factor/definition and Example
A walkthrough example of the discovery of the GCF of three numbers. Contains a definition as well.
Wolfram Research
Wolfram Math World: Greatest Common Divisors
An advanced investigation of Greatest Common Factors (Divisors) and a look at related algorithms and properties) comutative, associative, and more). Contains links to relevant topics.
Lawrence Hall of Science
The Math Page: Skill in Algebra: Common Factor
Here is a site that thoroughly explains many topics related to factoring out the greatest common factor from a sum or a polynomial expression. There are example problems, problems for the student to attempt, and answers to the student...
Oswego City School District
Regents Exam Prep Center: Factoring
From pulling out the common factors of a polynomial to giving hints on how to factor a trinomial that does not have a leading coefficient of 1, a comprehensive tutorial for factoring polynomials is given as well as practice, interactive...
McGraw Hill
Glencoe: Self Check Chapter Test Fractions and Decimals
Students are assessed on fractions and decimals. Topics include greatest common factor, improper fractions, and fractions as decimals. The self-checking test includes hints and solutions.
AAA Math
Aaa Math: Practice Finding Greatest Common Factor
This lesson contains a learning exercise in which the user has to find the greatest common factor and type it in. The exercise keeps track of how many right and wrong answers given and gives you a grade.
National Council of Teachers of Mathematics
The Math Forum: Finding the Greatest Common Factor of Two Numbers
Math Forum response to question about finding the greatest common factor by using the factoring tree method.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Greatest Common Factors, Least Common Multiples
Math Forum response to request for info on how to find greatest common factors, and how this compares to least common multiples. Explanation includes examples of each.
Khan Academy
Khan Academy: Factor With the Distributive Property
Practice applying the distributive property to factor numerical expressions (no variables). Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Goodwill
Gcf Global: Good at Math Game
Play this math game to help the robots and zombies as you practice addition, subtraction, multiplication, and division.