Join the parts
Add like-denominator fractions by joining equal units.
Explore this lesson →10 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- Keep both amounts on the same whole scale.
- Place their unit pieces together without overlap or duplication.
- The selected-piece counts add; the unit size stays fixed.
Something to notice
Ask why the denominator does not double when two collections are joined. Have the learner recreate the two original amounts from the total.
Try it. Change it. Explain it.
Open the lesson to use its pictures and controls. In How it works, connect the picture to the idea. In Play & discover, change the quantities and notice what stays the same. In Your turn, answer questions and use the explanation to check your reasoning.
You can ask for help, draw on the thinking pad, or listen to the question and answer options. Progress distinguishes independent work from work completed with help.
Let’s try it →Curriculum connection
Grade 4 · 4.NF · US Common Core
This lesson is mapped to these standards. A completed activity is practice evidence, not a claim of mastery. Content is checked against the linked official standards and its mathematical models are tested.