Curated OER
Greatest Common Divisor
In this greatest common divisor worksheet, students use prime factorization to determine the greatest common factors of two or more numbers. Explanations and examples are provided. This two-page worksheet contains ten problems.
Curated OER
Euclidean Algorithm
Students are introduced to the concept of a Greatest Common Divisor. They review the number systems. Students are told how the entire field of Number Theory primarily uses the integers. They are told the Fundamental Theorem of Algebra.
Curated OER
Greatest Common Divisor
In this math worksheet, students learn to find the greatest common divisor of two numbers. Students read and study the information and examples before solving 10 problems.
Amby Duncan-Carr
Greatest Common Factor/online Lesson
A complete lesson on Greatest Common Factors, including methods of finding, examples, and a practice multiple-choice quiz.
University of Regina (Canada)
University of Regina: Math Central: Greatest Common Divisor and Least Common Multiple
Learn about the greatest common divisor, the least common multiple, and the Euclidean Algorithm. This resource gives a description of each of these concepts, accompanied by several examples.
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.
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.
George Mason University
Margo Mankus: Investigating Lcm and Gcf Using Rods
This lesson plan is for an activity using rods (Cuisenaire Bars) to help students understand the concept of factors, in particular the LCM and GCF of two numbers.
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.
Texas Instruments
Texas Instruments: Gcd and Lcm
In this activity students use the Computer Algebra System CAS tool to compute greatest common divisor (GCD) and least common multiple (LCM) of numbers and expressions.
Purple Math
Purplemath: Lcm & Gcf
Purplemath shows an easy and orderly way to determine the GCF and LCM of any two numbers. Even large numbers won't be a challenge with this method.
Other
Greatest Common Factor Calculator
Free online calculator provides help with finding the greatest common 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.
Cuemath
Cuemath: Highest Common Factor
Explore the world of Highest Common Factor or Greatest Common Factor (GCF) by going through its various aspects and properties. Find answers to questions like what is the highest common factor for a group of numbers, easy ways to...
Wolfram Research
Wolfram Math World: Euclid's Algorithm
This site from Mathworld.com provides a very detailed description of Euclid's algorithm of common divisors and a method of finding the greatest.
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.
Math Slice
Math Slice: Greatest Common Divisor (Factor): Math Worksheets
This tool allows you to create worksheets where students must find the greatest common factor in a set of two to four whole numbers.