Find Rectangular Area with Unit Squares
Draw the stated rectangle as a unit-square grid.
About 15 minutes, plus any extended practice
Open lesson 1Distinguish Area from Perimeter
Count unit squares, add non-overlapping areas, and calculate boundaries and missing sides.
Before you begin
- Multiply equal groups; measure lengths in equal units.
Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.
Follow the lesson sequence
Add Areas of Non-Overlapping Parts
Use the supplied non-overlapping rectangular parts.
About 20 minutes, plus any extended practice
Open lesson 2Find Rectangle Perimeter
List the four supplied rectangle sides in order around the boundary.
About 15 minutes, plus any extended practice
Open lesson 3Find a Missing Side from a Perimeter
List the known sides and add them once.
About 20 minutes, plus any extended practice
Open lesson 4Review and transfer
After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.
Open the unit reviewGuest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.
Topic references
- Common Core State Standards, mathematics: 3.MD.C.5 — Count unit squares, add non-overlapping areas, and calculate boundaries and missing sides.
- Common Core State Standards, mathematics: 3.MD.C.6 — Count unit squares, add non-overlapping areas, and calculate boundaries and missing sides.
- Common Core State Standards, mathematics: 3.MD.C.7 — Count unit squares, add non-overlapping areas, and calculate boundaries and missing sides.
- Common Core State Standards, mathematics: 3.MD.D.8 — Count unit squares, add non-overlapping areas, and calculate boundaries and missing sides.
These references informed the topic selection. They do not certify complete standards alignment.