Multiplying fractions with like denominators


CCSS.MATH.CONTENT.5.NF.B.4 Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.

Click for individual state standards, or scroll to the bottom of the page.


45 minutes 


This lesson plan will explore how students can take what they already know about adding fractions with like denominators in order to grasp multiplying fractions with like denominators. It incorporates an instructional video, an editable presentation and an educational game that can be used to practice/reinforce the concept with assessment data. 

Technology required

The game Fish Lake can be played on iPad, Mac or Windows computers. Internet is required to log in to the game with username and password. If Internet access drops, students can continue playing and their progress will be saved on the device and uploaded to the server whenever access is available. Fish Lake is available free to schools participating in the Growing Math project.

Lesson Plan

1. VIDEO: Adding and Multiplying Fractions with Like Denominators

Start your lesson with this video on adding and multiplying fractions with like denominators.

Adding and multiplying fractions: Definitions and examples 3:33

This three-minute video begins with adding fractions with a common denominator. It explains that denominator is more than the number on the bottom, it is the number of parts the whole is divided into. Multiplying fractions with like denominators is shown, with examples, to be the same thing as adding the fraction multiple times.

Teaching Options

The video above is also available as editable PowerPoint presentation and as Google slides. Teachers may prefer to use these as part of a mini-lecture

2. GAME: Fish Lake

Have students play Fish Lake for 30 minutes. This game can be played on Mac, Windows and iPad. You can find the link on our games page. 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.


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 

6. Number & Operation

Multiply and divide decimals, fractions and mixed numbers; solve real-world and mathematical problems using arithmetic with positive rational numbers. – Multiply and divide decimals and fractions, using efficient and generalizable procedures, including standard algorithms.