Interactive
AAA Math

Aaa Math: Least Common Multiple

For Students 3rd - 8th Standards
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.
Unit Plan
Mangahigh

Mangahigh: Number: Least Common Multiple and Greatest Common Factor

For Students 4th - 7th Standards
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...
eBook
Mathigon

Mathigon: Math Foundations: Divisibility and Prime: Least Common Multiples

For Students 6th - 8th Standards
This lesson features practical applications for finding the least common multiples.
eBook
Mathigon

Mathigon: Math Foundations: Divisibility and Primes: Factors and Multiples

For Students 6th - 8th
This lesson focuses on factors and multiples; it explains each and provides practice activities and a quiz.
Handout
Quia

Ixl Learning: Least Common Multiple

For Students 5th - 6th Standards
Brush up on your math skills relating to the least common multiple then try some practice problems to test your understanding.
Interactive
Calculator Soup

Calculator Soup: Lcm Calculator Least Common Multiple

For Students 9th - 10th
The Least Common Multiple (LCM) is also referred to as the Lowest Common Multiple (LCM) and Least Common Divisor (LCD). For two integers a and b, denoted LCM(a,b), the LCM is the smallest positive integer that is evenly divisible by both...
Interactive
Mangahigh

Mangahigh: Number: Factors and Multiples

For Students 5th - 7th
List factor pairs to determine all factors and multiples of a number.
Activity
Texas Instruments

Texas Instruments: A Prime Investigation With 7, 11, and 13

For Teachers 6th - 8th
Students investigate the divisibility of 7, 11, and 13. They will also discover an interesting characteristic of six-digit multiples of 1001.
Whiteboard
SMART Technologies

Smart: Factors and Multiples

For Teachers 3rd - 6th Standards
Students are introduced to prime numbers, composite numbers, prime factorization, greatest common factor, and least common multiple in this SMART whiteboard activity.
Lesson Plan
Alabama Learning Exchange

Alex: Exploring Prime Numbers

For Teachers 3rd - 5th Standards
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...
Activity
Other

Eratosthenes' Prime Number Sieve

For Students 3rd - 8th Standards
Discover all the primes up to the number 400 by using this interactive table. Simply click on a number and its multiples disappear.
Activity
Varsity Tutors

Varsity Tutors: Hotmath: Graphing Calculator Practice Problems Number Theory

For Students 9th - 10th Standards
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...
Lesson Plan
Alabama Learning Exchange

Alex: My Favorite Number

For Teachers 4th - 7th
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...
eBook
Mathigon

Mathigon: Math Foundations: Divisibility and Primes: Divisibility Rules

For Students 6th - 8th
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...
Interactive
Other

Sieve of Eratosthenes

For Students 4th - 5th Standards
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...
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That Quiz

That Quiz: Factores

For Students 9th - 10th Standards
Interactive practice tests dealing with factors. Students will practice the prime factors, greatest common factor and least common multiple.
Graphic
Other

Project Happy Child: 100s Board Worksheets

For Students Pre-K - 1st Standards
Use these 100s Boards to have students check for divisibility by 2-12 and for square and prime numbers. Just find the links below the 100s board that has the directions printed right on top of the worksheet.
Website
PBS

Pbs Learning Media: Pizza Toppings

For Students 6th - 8th Standards
This Cyberchase video features Bianca who uses Venn Diagrams to make a pizza that satisfies the topping preferences of her friends.
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University of Vienna (Austria)

University of Vienna: Elementary Properties of Numbers

For Students 9th - 10th Standards
Quick interactive assessment which determines skill level on fraction equivalence, prime factorization, and common divisors/multiples.
Unit Plan
TED Talks

Ted: Ted Ed: Can You Solve the Fish Riddle?

For Students 4th - 8th
In this riddle, some endangered fish species are being transported by water and a storm causes them to be thrown overboard. Your task is to devise a way to rescue them. The video provides some pointers on how to approach the problem....
Handout
Cuemath

Cuemath: Highest Common Factor

For Students 9th - 10th Standards
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...
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Math Aids

Math Aids: Fractions Worksheets

For Teachers K - 1st Standards
Great resource for learning and practicing fractions and their different operations. Math worksheets are printable, may be customized, and include answer keys.
Unknown Type
Math Aids

Math Aids: Factors Worksheets

For Students K - 1st
Great resource for learning and practicing fractions and their different operations. Math worksheets are printable, may be customized, and include answer keys.
Unit Plan
Khan Academy

Khan Academy: Identify Composite Numbers

For Students 3rd - 5th Standards
Identify composite numbers less than 100. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.