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.
SMART Technologies
Smart: Factors and Multiples
Students are introduced to prime numbers, composite numbers, prime factorization, greatest common factor, and least common multiple in this SMART whiteboard activity.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems Number Theory
Practice using your graphing calculator for number theory problems, including prime factorization, greatest common factor, least common multiple, and scientific notation. If you get stumped or if you would like to check your work, then...