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.
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.
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...
Quia
Ixl Learning: Prime and Composite Numbers
Brush up on your math skills relating to prime and composite numbers then try some practice problems to test your understanding.
ClassFlow
Class Flow: Working With Prime and Composite Numbers
[Free Registration/Login Required] This flipchart allows students to practice working with prime and composite numbers. Students learn how to do prime factorization.
CK-12 Foundation
Ck 12: Arithmetic: Prime and Composite Numbers
[Free Registration/Login may be required to access all resource tools.] Identify and classify numbers as either prime or composite.
ClassFlow
Class Flow: Factoring, Prime and Composite
[Free Registration/Login Required] This flipchart defines factors, prime number, and composite numbers. It gives step-by-step instructions on how to list all the factors of a whole number and then identify the number as a prime number or...
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.
Scholastic
Scholastic: Study Jams! Math: Multiplication & Division: Prime Numbers
This site provides great practice on the concept of prime and composite numbers. Students can first learn about the topic by watching a step by step instruction video that also points out areas of concern. Finally, students can practice...
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
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.
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.
Curated OER
Clip Art by Phillip Martin: Prime and Composite Numbers
A clipart illustration by Phillip Martin titled "Prime and Composite Numbers."
ABCya
Ab Cya: Adventure Man Dungeon Dash Numbers
Adventure Man is back once again, but this time with the help of fearless friend Danger Dame! Help them dash their way through the Numbers Dungeon while collecting gold, gems, and answering questions about odd, even, prime, and composite...
E-learning for Kids
E Learning for Kids: Math: Ice Cream Shop: Numbers to 100,000,000
On this interactive site students learn to read and write large numbers in numerals, round numbers to millions, and locate prime and composite numbers.
Alabama Learning Exchange
Alex: Exploring Prime Numbers
Exploring Prime Numbers is a hands-on, minds-on math lesson plan that engages students in the discovery of prime numbers through the construction of multiplication arrays. Students then extend on their background knowledge of multiples...
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: The Prime Page
Find a quick, concise but complete explanation of prime numbers. A variety of related topics are covered such as: A table of the first 400 Prime Numbers, Do Primes ever stop?, the Prime Number Theorem and Twin Primes.
Wolfram Research
Wolfram Math World: Prime Number
Prime Numbers are defined with a glossary hyperlink to terms used in the definition. Lots of information and examples included. Lists many math-related links. Scroll down to the bottom of the page to see how prime numbers are used in the...
McGraw Hill
Glencoe: Self Check Quizzes 1 Prime Factors
Use Glencoe's randomly generated self-checking quiz to test your knowledge of prime factors. Each question has a "Hint" link to help. Choose the correct answer for each problem. At the bottom of the page click the "Check It" button and...
Other
Eratosthenes' Prime Number Sieve
Discover all the primes up to the number 400 by using this interactive table. Simply click on a number and its multiples disappear.
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.
Wyzant
Wyzant: Prime Factors Calculator
Students input a number to be factored and the WyzAnt calculator does the rest. Limitations include the fact that numbers which are negative or which contain primes bigger than 541 cannot be handled.
Elias Saab
Math Drills: Prime Factorization Quiz
This site is an interactive quiz which provides students with a prime factorization problem. Students input their solution and have the program evaluate it. Hints are available if the student needs them, and explanations are provided...
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: La Criba De Eratostenes
Reinforce your knowledge about prime and composite numbers. Geogebra plugin required.