Teach How to Add Fractions with Unlike Denominators

Mac is making homemade trail mix. She needs one-fifth of a cup of sultanas and one-third of a cup of nuts.

What is the quantity of ingredients that Mac will use?

To work out the answer to this question, your students need to understand that the question involves the addition of fractions with unlike denominators. Unlike denominators are fractions that have different denominators, e.g.one-fifth and one-third. There are several strategies that students can use when performing these types of operations with fractions. These include:

1. Pictorial models – Pictorial models are diagrams that can be drawn by students to visually represent problems with fractions.
2. Number Lines – Number lines are linear representations of a fraction that can be used to solve addition problems.
3. Fraction Notation – With an understanding of fraction notation comes the ability to solve addition problems using the standard algorithm.

To help your students better understand these three strategies for adding fractions with unlike denominators, the expert teacher team at Teach Starter has created this 30-slide teaching presentation. The presentation explores each strategy in detail using clear and detailed examples of each process. It also includes review activities that the students can work through independently as a means of checking for understanding.

This slide deck downloads in a Google Slides format. Simply project on your screen for a paperless lesson on adding fractions with unlike denominators!

Differentiate This Fractions Activity

If you’re looking for ways to differentiate this activity, here are some suggestions from our experienced teacher team:

• Provide Manipulatives – To help your less-confident students engage with and practice each strategy, provide manipulatives such as fraction strips and mini-whiteboards.
• Be the Teacher – Allow your more-confident students to demonstrate their knowledge by taking the lead during the review activities. Have students take turns coming up to the board and walking the class through the steps required to complete the questions.

Download to Add Fractions with Unlike Denominators

Use the Download button to access the Google Slides version of this resource. (Note: You will be prompted to make a copy of the Google Slides presentation before accessing it.)

This slideshow works best in Presentation mode.

This resource was created by Michael Bailey, a teacher in New York and a Teach Starter collaborator.

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