McGraw Hill
Glencoe: Self Check Quizzes 1 Greatest Common Factor
Use Glencoe's randomly generated self-checking quiz to test your knowledge of how to find the greatest common factor. Each question has a "Hint" link to help. Choose the correct answer for each problem. At the bottom of the page click...
Discovery Education
Discovery Education: Web Math: Greatest Common Factor
This WebMath site contains a tool for locating the greatest common factor. Simply plug in the numbers and you are on your way! Use it to check your answers.