Go Math! Grade 4, Chapter 13: Perimeter and Area
In this unit, your child finds the perimeter and area of rectangles with formulas, and works backwards to find an unknown side. They solve real problems, like how much fence or carpet a space needs, and find the area of shapes made of rectangles. It follows the measurement unit and finishes the year.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 13?
- Finding the perimeter and area of rectangles with formulas, finding an unknown side, and splitting combined shapes into rectangles to find their area. Learn more: Using area and perimeter to solve real problems
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
Sofia makes a square picture frame. The perimeter of the frame is 64 inches. How long is each side of the frame?
- 16 inches
- 256 inches
- 32 inches
How you can help
- Measure a bed or a table with a tape measure. Ask your child how much trim would go around it and how much space the top covers, and which number is the area.
- Design a pretend play space on paper with 24 feet of fence. Ask your child how many different rectangles they can make, and which gives the most room.
- Draw an L-shaped room on paper, like a 6-by-4 rectangle joined to a 3-by-2 one. Have your child find its area by splitting it into rectangles: 24 + 6 = 30.
Where kids can get stuck
- Adding just the length and width for perimeter, so a 7-by-3 rectangle gets 10 instead of 20.
- Multiplying when the question asks for the distance around, mixing up area and perimeter.
- Forgetting to divide when the area and one side are given, and multiplying them instead.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- area
- The space inside a flat shape, measured in square units.
- perimeter
- The distance all the way around a flat shape.
- formula
- A rule written with symbols, like area = length × width.
- square unit
- A square with sides 1 unit long, used to measure area.
- length
- How long something is from end to end.
- width
- How wide something is from side to side.
Want to help your child master area and perimeter problems?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
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Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Go Math! Grade 4 Chapter 13 cover?
Go Math! Grade 4 Chapter 13 covers this math standard. Each one links to what it means, sample questions, and teaching strategies.
- 4.MD.A.3: Solve problems with the area and perimeter of rectangles.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.