Find the missing side or complete rows
Connect division to an array or a rectangle without losing leftover items.
Explore this lesson →10 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- Complete rows have equal size. Their product accounts for the items inside the rectangle.
- Leftover countable items stay outside complete rows.
- A literal area divided by a side length gives another length; distinguish square metres from metres.
Something to notice
Ask the learner to point to what each number counts or measures. Can they reconstruct all items including leftovers, or explain why a rectangular area's missing side has a length unit?
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.NBT · 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.