Adding fractions with like denominators


CCSS.MATH.CONTENT.4.NF.B.3.A Understand addition and subtraction of fractions as joining and separating parts referring to the same whole.

CCSS.MATH.CONTENT.4.NF.B.3.D Solve word problems involving addition and subtraction of fractions referring to the same whole and having like denominators, e.g., by using visual fraction models and equations to represent the problem.

[For state-specific standards, click here.]


45 minutes


This lesson plan will explore how students can add fractions with like denominators to determine the sum of fractions. It incorporates two instructional videos, an editable presentation and educational game that can be used to practice/reinforce the concept with assessment data.    

Technology Required

The teacher (or student, if learning at home) will need a computer, phone or tablet with an Internet connection to play the video. For students at home without Internet access, the teacher can print out the attached PDF or PowerPoint for students to study. The game required plays on Windows or Mac computers and on iPad. A Chromebook version will be available by April.

Lesson Plan

1. VIDEO: Adding Like Fractions

Start your lesson with this one-minute video on adding fractions with like denominators.

Alternate format : POWERPOINT: Adding Fractions with Like Denominators

This presentation provides the information in the video viewed at the beginning of the lesson as a PowerPoint or PDF.

For a PDF version, go here. 

For an editable PowerPoint version, go here. 

2. Game Play

Have students play Fish Lake for 30 minutes. This lesson is most effective when introduced towards the beginning of Fish Lake gameplay since the math ties into the math in Level 3. Students who master this standard will be able to advance within the game. Students who have trouble with this standard will receive individual instruction within the game to teach and reinforce this concept. 

3. Reinforce with another video

Common denominators can help you determine what’s fair

This two-minute video gives examples of how fractions with like denominators can be used to see if everyone is doing their fair share of the work or eating a fair share of the pizza.

4. Related Lesson – Introducing Fractions

If your students are struggling with adding fractions with common denominators, they may need a review of the introduction to fractions, including defining numerator and denominator.


You can view your students’ progress on mastering these standards by viewing your Fish Lake Teacher Reports. You can access the Fish Lake reports here. 


Arizona (AZ), New Mexico (NM), North Dakota (ND), South Dakota (SD), and Oregon (OR) have all adopted the math standards covered in the Common Core Standards. 

Minnesota (MN) Math Standard 

4. Number and Operation 

Represent and compare fractions and decimals in real-world and mathematical situations; use place value to understand how decimals represent quantities. – Use fraction models to add and subtract fractions with like denominators in real-world and mathematical situations. Develop a rule for addition and subtraction of fractions with like denominators.

1 thought on “Adding fractions with like denominators

  1. Pingback: Introducing Fractions – Growing Math

Leave a Reply

Your email address will not be published. Required fields are marked *