Grade 5 · Mathematics · 25 minutes

Add unlike fractions

Use equal-sized wholes for a half and a third. Rename fractions in equal-sized units before adding.

Mr. S Teaches · Starter mini-lesson · elem-5-add-unlike-fractions

Learning objective

Explain and practice add unlike fractions using the activity and evidence, then show the reasoning behind an answer.

Gather your materials

Paper and pencil
Counters, blocks or paper pieces
A ruler, clock model or grid when named in the steps

Use the items named in the teaching steps; paper models or adult-prepared photographs can replace physical equipment.

Common Core skill focus

5.NF.A.1

Use equivalent fractions to add and subtract unlike denominators.

Read the official standard ↗

Code and grade verified 2026-11-03. This mini-lesson addresses a selected skill, not the entire standard.

Teach it step by step

Use equal-sized wholes for a half and a third.
Partition each into sixths.
Rename 1/2 as 3/6 and 1/3 as 2/6.
Add the counts of sixths and simplify if possible.

Watch, notice, discuss

Video choices for this lesson

2 choices

Preview a video, then choose what fits your learners. “Show to class” opens a larger view; use the player’s play and full-screen controls when you’re ready.

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OPTION 1 · YOUTUBE

Adding Fractions with Unlike Denominators | Math with Mr. J

By Math with Mr. J

Connect this video to the lesson on add unlike fractions. Pause to try an example together.

Open on YouTube: Adding Fractions with Unlike Denominators | Math with Mr. J (opens a new tab) ↗

OPTION 2 · YOUTUBE

How to Add Fractions with Unlike Denominators | Math with Mr. J

By Math with Mr. J

Connect this video to the lesson on add unlike fractions. Pause to try an example together.

Open on YouTube: How to Add Fractions with Unlike Denominators | Math with Mr. J (opens a new tab) ↗

After watching

Use a model to explain why unlike fractions need equal-sized units before addition.

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Make the thinking visible

Example to work through together

1/2 + 1/3 = 3/6 + 2/6 = 5/6. The pieces must have equal size before they can be counted together.

Try the starter activity

Use sixths to model 1/2 + 1/3.

Student practice

Add 1/4 + 1/2 using a model and equivalent fractions.

Quick check for understanding

Find the sum.

Sample answer and teacher guidance

Sample answer: 3/6 + 2/6 = 5/6.

Listen or look for: 1/4 + 2/4 = 3/4.

Invite the learner to explain, demonstrate, draw or dictate their reasoning. Revisit a teaching step when the explanation is unclear.