Unit Plan
CK-12 Foundation

Ck 12: Elem Math: Finding the Least Common Denominator

For Students 4th - 5th
[Free Registration/Login may be required to access all resource tools.] In this learning module, students must find the least common denominator for the fractions they are presented with. Includes video demonstrating a sample problem...
Handout
Varsity Tutors

Varsity Tutors: Hotmath: Algebra Review: Least Common Denominator

For Students 9th - 10th Standards
Find a quick, concise explanation of how to find the least common denominator for fractions or rational expressions. Examples are given and clearly explained.
Handout
Other

Help With Fractions: Least Common Denominator

For Students 3rd - 8th Standards
The rules for finding the least common denominator are clearly explained at this website. Two different methods are given. This is an excellent place to get step by step explanations for working with fractions.
Interactive
Calculator Soup

Calculator Soup: Lcd Calculator Least Common Denominator

For Students 9th - 10th
Use this Least Common Denominator Calculator to find the lowest common denominator (LCD) of fractions, integers and mixed numbers. Finding the LCD is important because fractions need to have the same denominator when you are doing...
Handout
Homeschool Math

Homeschool Math: Finding the (Least) Common Denominator

For Teachers 5th
Students learn about finding a common denominator in fraction addition and subtraction.
Unit Plan
CK-12 Foundation

Ck 12: Elem Math: Subtracting Fractions With Different Denominators

For Students 4th - 5th Standards
[Free Registration/Login may be required to access all resource tools.] In this learning module, students must find the least common denominator of two fractions in order to subtract one from the other. Includes video demonstrating a...
Unknown Type
Khan Academy

Khan Academy: Common Denominators

For Students 3rd - 5th Standards
In this exercise, students practice finding common denominators. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Whiteboard
ClassFlow

Class Flow: Finding the Common Denominator

For Teachers 6th - 8th
[Free Registration/Login Required] This flipchart presents a method for finding the common denominator of fractions.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: Finding Common Denominators to Add

For Teachers 5th - 8th Standards
Part (a) of this task asks learners to find and use two different common denominators to add the given fractions. The purpose of this question is to help students realize that they can use any common denominator to find a solution, not...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: Finding Common Denominators to Subtract

For Teachers 5th - 8th Standards
Part (a) of this task asks students to use two different denominators to subtract fractions. The purpose of this is to help students realize that any common denominator will work, not just the least common denominator. Part (b) does not...
Whiteboard
Other

Active Maths Limited: Adding & Subtracting Fractions: Whiteboard Resources

For Students 3rd - 8th Standards
This is an excellent resource to visually illustrate adding and subtracting fractions by finding the lowest common denominator.
Unit Plan
AAA Math

Aaa Math: Least Common Denominator

For Students 3rd - 8th
This site explains how to find the least common denominator. Also provides games to work on this skill.
Lesson Plan
Better Lesson

Better Lesson: Finding the Least Common Multiple (Lcm)

For Teachers 6th Standards
The LCM is a useful tool to use when comparing fractions and finding common denominators.
Unit Plan
CK-12 Foundation

Ck 12: Arithmetic: Sums of Fractions With Different Denominators

For Students 5th - 7th
[Free Registration/Login may be required to access all resource tools.] In this lesson students find sums of fractions with different denominators by renaming them with common denominators. Students examine guided notes, review guided...
Unit Plan
AAA Math

Aaa Math: Adding Fractions With Different Denominators

For Students 9th - 10th Standards
This personal site explains how to add fractions with different denominators by finding the least common denominator. Gives problems and games to practice this skill.
Activity
Scholastic

Scholastic Math Maven's Mysteries: The Mystery of Pirate Ringold's Lost Treasure

For Teachers 3rd - 8th
In this Math Maven mystery, read the legend of Pirate Ringold and his treasure and help Frieda Finditall figure out how much gold there is left to find on this old ship. Your knowledge about addition and subtraction with fractions will...
Activity
Sophia Learning

Sophia: Addition and Subtraction of Rational Expressions

For Students 9th - 10th Standards
Use the examples to find the least common denominator in order to add and subtract rational expressions.
Handout
Oswego City School District

Regents Exam Prep Center: Add and Subtract Rational (Fractional) Expressions

For Students 9th - 10th Standards
Add and subtract rational expressions like a pro after you use this site. Finding common denominators is made easy with this tutorial. Try the example problems to test your knowledge, then check the solutions. The 'Topic Index' page...
Unit Plan
CK-12 Foundation

Ck 12: Arithmetic: Differences of Fractions

For Students 6th
[Free Registration/Login may be required to access all resource tools.] Find differences of fractions with different denominators by renaming them with a common denominator.
Unit Plan
Other

Mr. Perez Online Math Tutor: Solving Rational Equations

For Students 9th - 10th
The mathematics tutorial investigates how to simplify rational equations, find the least common denominator as well as how to solve rational equations. There are notes, examples and an interactive applet as well as a vocabulary puzzle.
Activity
Lawrence Hall of Science

The Math Page: Skill in Algebra: Equations With Fractions

For Students 9th - 10th Standards
Here is a site that clearly and thoroughly explains solving equations with fractions by finding the least common multiple of the denominators and clearing the fractions. There are example problems solved, problems for the student to...