Grades 4–5 Skill Standards: CCSS 4.MD.A.3

Perimeter vs Area — Knowing the Difference (Grades 4–5)

Perimeter is the distance around a shape (add up all the side lengths); area is the space inside (square units). It's easy to mix them up — fencing a yard is perimeter; sodding it is area. For a rectangle, perimeter = 2 × (length + width) and area = length × width.

What it is

Understanding perimeter vs area

Perimeter is the distance around a shape (add up all the side lengths); area is the space inside (square units). It's easy to mix them up — fencing a yard is perimeter; sodding it is area. For a rectangle, perimeter = 2 × (length + width) and area = length × width.

Key Idea

Perimeter is the distance around a shape (add up all the side lengths); area is the space inside (square units). It's easy to mix them up — fencing a yard is perimeter; sodding it is area. For a rectangle, perimeter = 2 × (length + width) and area = length × width.

Worked Example

Seeing it in action

1
Worked example

A rectangle is 5 by 3. Find its perimeter and area.

Perimeter = 2 × (5 + 3) = 16 units. Area = 5 × 3 = 15 square units.

Visual model

Perimeter goes around; area fills inside.

Interactive Check

Try a few

Rectangle 4 by 6 — perimeter?
Answer: 20

2 × 10.

Square side 5 — area?
Answer: 25
Rectangle 2 by 8 — perimeter and area?
Answer: perimeter 20, area 16
Free game

Perimeter Patrol

A calm tile-grid game for building and reading area and perimeter.

Play: Perimeter Patrol

Ready for the interactive lab?

Practice perimeter vs area in Numeris with instant feedback.

Practice this skill in the Lab

Put the reasoning on paper.

Try six fraction, angle, perimeter and area questions with explained answers, for grades 4–6.

Free printable · 3 pages
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Free Math Sample

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