Math Is Fun
Math Is Fun: Prime Factorization
Find a definition or prime numbers and prime factorization, as well as examples on how to find the prime factors of 12 and 147. Also, follow a link to a Prime Factorization Tool.
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.
Discovery Education
Discovery Education: Web Math: Factor an Integer
WebMath gives a calculator to give all the factors of a number. Drop down menu can select just prime factors of number entered. Also discusses the definition of a factor.
Discovery Education
Discovery Education: Web Math: Find the Least Common Multiple of Some Numbers
Use this site to find the Least Common Multiple (LCM) of any set of numbers. Simply type in your numbers, and the site will provide the answer complete with a full explanation.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Composite Numbers
Find a quick, concise explanation of Composite Numbers. Several examples are given and clearly explained. Prime numbers are also described.
CK-12 Foundation
Ck 12: Elem Math: Arbitrary Digits Numbers Up to 100000
[Free Registration/Login may be required to access all resource tools.] Students practice making large and small numbers with whole numbers.
CK-12 Foundation
Ck 12: Elem Math: Prime Factorization
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems about prime factorization.
CK-12 Foundation
Ck 12: Elem Math: Finding the Range of Missing Numbers Given a Statement
[Free Registration/Login may be required to access all resource tools.] For this learning module, students are given a division question where a digit is missing in the dividend and they are told how many digits are in the quotient....
CK-12 Foundation
Ck 12: Elem Math: Greatest Common Factor
[Free Registration/Login may be required to access all resource tools.] For this learning module, students are asked to identify the greatest common factor of two whole numbers that are one or two digits. Includes video demonstrating a...
CK-12 Foundation
Ck 12: Elem Math: Identifying Prime or Composite Numbers
[Free Registration/Login may be required to access all resource tools.] For this learning module, students are asked to identify prime and composite numbers. Includes video demonstrating a sample problem [1:30] and a set of practice...
Other
Help With Fractions: Prime Numbers Chart
Prime and composite numbers are defined on this website. A prime number chart is also included for all prime numbers under 10,000.
Other
Help With Fractions: The Greatest Common Factor
Two different methods of finding the greatest common factor are explained at this one page website. It is very easy to follow the step by step directions.
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.
Mangahigh
Mangahigh: Number: Multiply and Divide Whole Numbers by 10, 100 and 1000
This site provides students practice with the concept of multiplying and dividing whole numbers. Students can learn about the topic by completing an interactive tutorial. Students can then take a ten question timed test to practice the...
Khan Academy
Khan Academy: Factors and Multiples Intro
Explains what factors are and uses images to visualize the different factors of whole numbers. Next, discusses how to find factors without images and how to identify factor pairs. Multiples are then explained and how they relate to...
National Council of Teachers of Mathematics
The Math Forum: Divisibility Test Game "Nullo"
The lesson plan for two to four players engaged in an active card game to determine the divisibility of a number. The materials needed, the rules of the game, and the methods of scoring are all explained for the teacher.
University of Waterloo (Canada)
Wired Math: Primes and Prime Factors [Pdf]
Explore primes, prime factors, and composites using this collection of worksheets. Lots of detailed examples, interesting math facts, and colorful visuals. Acrobat Reader required.
Cool Math
Coolmath: Coolmath4kids: Math Ficher Prime Numbers
Hop into your boat and go fishing for the prime numbers between 1 and 100!
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.
Cool Math
Coolmath: Gcf's and Lcm's Greatest Common Factor
Understand how to find the greatest common factor.
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.
Khan Academy
Khan Academy: Factor Pairs
Practice finding factor pairs for whole numbers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Identify Factors and Multiples
Demonstrate understanding of factors and multiples. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
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.