Khan Academy
Khan Academy: Prime Factorization
A practice quiz on the prime factorization of numbers. Includes hints.
Mangahigh
Mangahigh: Number: Prime Factoring
Explore prime factors and what the missing exponent could be.
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.
That Quiz
That Quiz: Factores
Interactive practice tests dealing with factors. Students will practice the prime factors, greatest common factor and least common multiple.
Math Is Fun
Math Is Fun: Mathopolis: Practice Prime Factorization
A set of six multiple-choice questions practicing prime factorization. A help page is available for further study.
Khan Academy
Khan Academy: Prime and Composite Numbers Intro
Discusses factors, prime and composite numbers, and why the number 1 is not prime or composite. Includes practice problems throughout, along with explanations of solutions.
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...
Khan Academy
Khan Academy: Identify Prime Numbers
Identify prime numbers less than 100. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Cuemath
Cuemath: Least Common Multiple
Learn about the properties of Least Common Multiples (LCM) and the three methods to find the LCM. Included are solved examples and interactive problems for review.
Mangahigh
Mangahigh: Number: Least Common Multiple and Greatest Common Factor
This site provides students practice with the concept of least common multiples and greatest common factors. Students can learn about the topic by completing an interactive tutorial. Students can then take a ten question timed test to...
AAA Math
Aaa Math: Prime and Composite Numbers
This math tutorial offers an explanation of prime and composite numbers and lets students practice finding them.
AAA Math
Aaa Math: Least Common Multiple
This tutorial offers an explanation of least common multiples, practice finding them and a game to play. There is a lot of information available at this location.
PBS
Pbs Learning Media: Pizza Toppings
This Cyberchase video features Bianca who uses Venn Diagrams to make a pizza that satisfies the topping preferences of her friends.
Other
Sieve of Eratosthenes
Named after the Greek Mathematician. This classic method of finding prime numbers is also great for teaching about factors and multiples. The visnos sieve allows for multi colored squares this allows identification of any numbers prime...
Mathigon
Mathigon: Math Foundations: Divisibility and Primes: Divisibility Rules
There are a few different rules that can make it easy to check if a number is divisible by another. In this lesson you will learn some of them such as,any number that ends in 0, 2, 4, 6, or 8 is divisible by 2, divisibility by 5 we...
University of Vienna (Austria)
University of Vienna: Elementary Properties of Numbers
Quick interactive assessment which determines skill level on fraction equivalence, prime factorization, and common divisors/multiples.
Math Aids
Math Aids: Factors Worksheets
Great resource for learning and practicing fractions and their different operations. Math worksheets are printable, may be customized, and include answer keys.
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...
Alabama Learning Exchange
Alex: My Favorite Number
The activity allows students to review many of the number theory concepts. Students will pick a composite number write verbal expressions about the number, find the factors, prime factorization, list multiples, draw a cartoon character...
Math Aids
Math Aids: Fractions Worksheets
Great resource for learning and practicing fractions and their different operations. Math worksheets are printable, may be customized, and include answer keys.
Khan Academy
Khan Academy: Identify Composite Numbers
Identify composite numbers less than 100. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Other
Stat Soft: Statistics Glossary
Dozens of statistical terms are defined and illustrated in this glossary.
The Math League
The Math League: Fractions
This tutorial covers all types of fractions with simple explanations on how to work with them.