Interactive
Curated OER

Least Common Multiple or Least Common Denominator

For Students 5th - 6th
Fifth and sixth graders solve 12 math problems by finding the least common multiple or least common denominator. They type the answer into the text box.
Activity
Curated OER

Finding Common Denominators to Subtract

For Teachers 5th Standards
Subtracting fractions with unlike denominators can be overwhelming, but in this task, 5th graders work systematically to break down the procedure through three questions. The first two questions ask for pictures to be drawn along...
Worksheet
Curated OER

Least Common Multiple

For Students 6th - 9th
Give students detailed instructions on how to find the Least Common Multiple as well as practice with this thorough introductory worksheet. Instructions for this worksheet include an explanation of both guess and check as well as prime...
Worksheet
Curated OER

Subtraction Fractions, Common Denominators

For Students 3rd - 4th Standards
How many steps do you need to subtract fractions with common denominators? Thirty problems await your kids, all with outlined steps for easy solving. Some fractions need to be reduced, while others will be solved after one step. An...
PPT
Curated OER

Fraction X--Adding Unlike Denominators

For Teachers 4th - 5th
In this math PowerPoint, the process of adding fractions with unlike denominators is broken down into a logical, easy-to-follow sequence of steps. Definitions and examples of multiples, least common multiple, and least common denominator...
Lesson Plan
Curated OER

Discovering New Units

For Teachers 4th - 6th
Students use Cuisenaire rods to explore common denominators. In this fractions lesson, students build Cuisenaire representations of fractions, then find their equivalent counterparts to find the common denominator.
Activity
Education Development Center

Adding Fractions with Unlike Denominators

For Teachers 4th - 5th Standards
If the fractions don't have a common denominator, make them have one. Learners first read and analyze a conversation of pupils trying to add 2/5 and 1/2. They compare the process of adding fractions to the process of adding quantities...
PPT
Curated OER

Fraction XII: Subtracting Unlike Denominators

For Teachers 4th - 5th
This fractions PowerPoint defines and gives examples of multiples and least common multiple, then models how to list multiples and circle the least common multiple. Each step to use in subtracting fractions with unlike denominators is...
Assessment
PBS

Working with Common Denominators: Assessments

For Students 4th - 6th Standards
Now that the practice is over, see if young mathematicians can utilize their new skills on finding common denominators and adding fractions. The assessment contains one map challenge and follows with skills practice. 
Worksheet
K-5 Math Teaching Resources

Adding Mixed Numbers (Unlike Denominators)

For Students 3rd - 6th Standards
Mix things things up in your elementary math class with a series of problem-solving exercises. Presented with a series of mixed number word problems, young mathematicians are asked to solve them by using either visual fraction...
Lesson Plan
1
1
Illustrative Mathematics

Listing Fractions in Increasing Size

For Teachers 3rd - 5th Standards
Increase the depth of your class's fractional number sense with this number-ordering activity. Given four fractions, each with different numerators and denominators, young learners are asked to place them in order from smallest to...
Lesson Plan
Illustrative Mathematics

Multiples and Common Multiples

For Teachers 6th - 7th Standards
Learners are asked to find multiples and common multiples of two numbers. They must take their findings and find a pattern between the numbers and explain their reasoning. Use this resource with The Florist Shop activity in this series...
Lesson Plan
West Contra Costa Unified School District

Lowest Common Multiple through the Grades

For Teachers 8th - 10th Standards
The LCM will be your new BFF. Learners review least common multiple and least common denominator applications, mostly on fractions, from middle school. Scholars then see how the LCM can be applied to various types of problems from...
Interactive
2
2
Scholastic

Study Jams! Add & Subtract with Unlike Denominators

For Students 5th - 7th Standards
Your bakers might not realize that they need to know how to add with unlike denominators in order to figure out how much milk they need for a recipe. In order to make brownies and cookies, this lesson teaches how to find a common...
Interactive
Online Math Learning

Word Problems That Use GFC or LCM

For Students 4th - 6th
This is a webpage that contains five word problems requiring learners to find the least common multiple or least common denominator.
Lesson Plan
Curated OER

The 3 R's of Common Denominators (Language)

For Teachers 4th - 6th
Students solve various word problems that deal with common denominators, and write the mathematical explanations they used to obtain the solutions.
Lesson Plan
Ohio Department of Education

Actions with Fractions: Adding and Subtracting Fractions with Common Denominators

For Teachers 3rd - 5th Standards
Fourth graders develop a conceptual understanding of fractions and begin to add and subtract fractions with like denominators. Included is a worksheet to assess readiness and a teacher's checklist showing class understanding at a...
Interactive
Curated OER

Adding and Subtracting Fractions (With Unlike Denominators)

For Students 5th - 6th
In this math worksheet, students subtract and add fractions with unlike denominators. Students solve the problem in steps. They are given examples of how to solve the problems.
Lesson Plan
Curated OER

Fractions of A Pizza

For Teachers 3rd - 5th
Students view a large illustration of a pizza with parts of velcro.  In this addition and subtraction of fractions lesson, students solve problems based on the pieces missing from the pizza. Students take a fraction quiz. Order a...
Lesson Plan
EngageNY

Least Common Multiple and Greatest Common Factor

For Students 6th Standards
Find the common denominator between prime factors, factor trees, and the distributive property. Scholars learn to find the least common multiple and greatest common factor of pairs of numbers. They rotate through stations to connect...
Lesson Plan
Curated OER

Reduction to Common Denominator

For Teachers 4th - 5th
Students compare two fractions with different denominators. In this fractions lesson, students find the least common multiple in order to find a common denominator with two fractions. Once they have a common denominator, they compare the...
Worksheet
Curated OER

Adding Mixed Numbers and Fractions

For Students 5th - 6th
Once scholars have a grasp on adding fractions, it's time to throw some mixed numbers into the equation! Each of these 14 addition problems has one mixed number and one proper fraction. Skills here include finding a common denominator,...
Worksheet
PBS

Working with Common Denominators: Activities and Supplemental Materials

For Students 4th - 6th Standards
Enjoy these straightforward and simple worksheet pages that practice with different denominators. The practice starts simple with adding fractions together and then works on a recipe that needs to be tripled. 
Lesson Plan
1
1
EngageNY

Adding and Subtracting Rational Expressions

For Students 10th - 12th Standards
There's a fine line between a numerator and a denominator! Learners find common denominators in order to add and subtract rational expressions. Examples include addition, subtraction, and complex fractions.