Parent guide · Grade 3 Math · Unit 7

Lesson 7.2 Area = Length × Width

Written for the parent. Read the Say this lines aloud as they are, or in your own words. Answers for you are marked Listen for.

At a glance

Time: 5 sessions of 25–30 minutes
Goal: Find the area of a rectangle by multiplying.
You need: Pencil and crayons
Print: Worksheet A · Worksheet B · the lesson page (it also has a short video (4:43))

Steps

Warm-up
Do this: Ask these out loud. Your child answers out loud; no paper needed.
- Ask: “8 × 9” Listen for: 72
- Ask: “9 × 9” Listen for: 81
- Ask: “8 × 5” Listen for: 40
- Ask: “4 × 10” Listen for: 40
- Ask: “4 × 6” Listen for: 24
Teach the new idea
Say this: “The rows of tiles are an array, so area = length × width.”
Say this: “A 6 ft by 4 ft rug covers 24 square feet.”
Say this: “Length: how long a side is.”
Say this: “Width: how wide the shape is.”
Show how
Show: Find the area of a rectangle 9 cm long and 3 cm wide.
$rectangle$
Say this: “Area = length × width”
Say this: “9 × 3 = 27”
Say this: “Area = 27 square centimeters”
Answer: 27 square centimeters
Show: A rectangle has an area of 50 square centimeters. Its length is 10 cm. What is its width?
Say this: “Area = length × width, so 10 × ___ = 50.”
Say this: “50 ÷ 10 = 5”
Answer: 5 cm
Practice together
Do this: Your child does these with you. Let them try first; help only after a real try.
Ask: Find the area of a rectangle 5 cm long and 3 cm wide.
$rectangle$
Listen for: 15 square centimeters
If stuck: Area = length × width
Ask: Find the area of a rectangle 2 cm long and 3 cm wide.
$rectangle$
Listen for: 6 square centimeters
If stuck: Area = length × width
Ask: Find the area of a rectangle 4 cm long and 6 cm wide.
$rectangle$
Listen for: 24 square centimeters
If stuck: Area = length × width
7 more practice items on the lesson page, and on Worksheet A and Worksheet B.
Watch for
- Adding length and width.
Game: Garden Planner
On graph paper, design a garden bed with an area of 24 squares. How many different rectangles can you make? Which has the shortest fence (perimeter)?
Narration
Say this: “Tell me what you learned today. Show me with your hands or the counters if you like.”
Listen for: Find the area of a rectangle by multiplying.
Daily habit
Fact drill. Square numbers: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100.

Spread over the week

5 sessions of 25–30 minutes. Stop while it is still going well.

Session 1. Warm-up, then teach the new idea (steps 1 and 2).
Session 2. Warm-up again, then show how with the examples.
Session 3. Practice together, then play the game.
Session 4. More practice on the worksheet, and the daily habit.
Session 5. Quick check: narration and a few practice items. Move on when it is mostly right.