Module 2 lesson (1-2)

HMH Into Math

- Module 2

3rd Grade

Perimeter

Perimeter​

I can use addition and multiplication to find the perimeter of plane figures.

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When do we need to find the perimeter?

• Solving how much fence we need to go around a yard?

• Solving how long is your table?

• Solving how long are the two whiteboards in this classroom?

• Solving how long is your math book?

How do we find the perimeter?

We find perimeter by counting the units around the shape, or adding the length of all of the sides together.

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Perimeter=L+L+W+W​

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Multiple Choice

What is the PERIMETER of this shape?

• 20 inches

• 21 inches

• 14 inches

• 6 inches

Multiple Choice

What is the perimeter of this shape?

• 4 units

• 10 units

• 20 units

• 6 units

Multiple Choice

What is the perimeter?

• 21 ft

• 10 ft

• 20 feet

• 20 square feet

Multiple Choice

what is the perimeter of the triangle?

• 14 m

• 15 m

• 16 m

• 20 m

Multiple Choice

What is the perimeter of the rectangle? (Hint: top matches the bottom, left matches the right!)

• 48 feet

• 27 feet

• 28 feet

• 30 feet

Lesson 1-
Relating

Multiplication

& Area

Enya wants to cover a kitchen counter with 18 square
tiles or circle tiles. Which tile shape covers the counter
completely? Show how Enya can find which tile shape
covers the counter completely.

SPARK YOUR LEARNING

Show how Enya can find which tile shape
covers the counter completely.

SPARK YOUR LEARNING

BUILD UNDERSTANDING

Mr. Gordon's garden is in the shape of a rectangle. It is made
from 4 unit squares. How might Mr. Gordon’s garden look?
Use a geoboard and rubber bands. Then show two different
ways Mr. Gordon’s garden might look.

BUILD UNDERSTANDING

Mr. Gordon's garden is in the shape of a rectangle. It is made
from 4 unit squares. How might Mr. Gordon’s garden look?
Use a geoboard and rubber bands. Then show two different
ways Mr. Gordon’s garden might look.

BUILD UNDERSTANDING

How are the figures different? How do you know?

How are the figures alike? How do you know?

BUILD UNDERSTANDING

Possible answer: There are 4 unit squares in each
figure. I can count the unit squares.

How are the figures different? How do you know?

How are the figures alike? How do you know?

Possible answer: There are 4 unit squares in each
figure. I can count the unit squares.

BUILD UNDERSTANDING

Suppose Mr. Gordon wants to change the shape of his
garden from a rectangle to any figure. He still wants the
garden to be made from 4 unit squares. Draw another
figure that Mr. Gordon could make.

BUILD UNDERSTANDING

Suppose Mr. Gordon wants to change the shape of his
garden from a rectangle to any figure. He still wants the
garden to be made from 4 unit squares. Draw another
figure that Mr. Gordon could make.

WHAT IS IT?
AREA

The area measures the number of
unit squares needed to cover a surface.
A unit square has an area of 1 square
unit.

CONNECT TO VOCABULARY

UNIT SQUARE

A unit square is a square with
a side length of 1 unit.

WHAT IS IT?

CONNECT TO VOCABULARY

Area on a
Grid

A grid has vertical and horizontal
lines that form a square. Each
square measures 1 sq. unit.

Let's count how many squares
the blue rectangle covers.

Area on a
Grid

There are 35 squares.

This means that the rectangle
has an area of 35 square units.

3 5 S Q U A R E

U N I T S

ACTIVITY

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ACTIVITY

12

12

10

CHECK UNDERSTANDING

Dana draws this figure. Shade each unit square
in the?figure.?What is the area? _____

CHECK UNDERSTANDING

Dana draws this figure. Shade each unit square
in the?figure.?What is the area? ____

Lesson 2-
Measure
areas by

counting unit

squares

Dom plans to use either large square tiles or small
square tiles to cover a wall space without gaps or
overlaps. Show how Dom can cover the wall space.

SPARK YOUR LEARNING

Show how Dom can cover the wall space.
SPARK YOUR LEARNING

How many large square tiles
would Dom use? How many
small square tiles would Dom
use?
6 large tiles; 24 small tiles

BUILD UNDERSTANDING

Miwa thinks she needs six 1-inch square tiles to cover
the rectangle below. Gregg thinks he needs ten 1-inch
square tiles to cover the same rectangle. Draw to show
how the tiles might look.

BUILD UNDERSTANDING

Miwa thinks she needs six 1-inch square tiles to cover
the rectangle below. Gregg thinks he needs ten 1-inch
square tiles to cover the same rectangle. Draw to show
how the tiles might look.

BUILD UNDERSTANDING

Whose statement makes sense? Explain.

How many 1-inch square tiles would you use to cover the
rectangle? How do you know?

BUILD UNDERSTANDING

Whose statement makes sense? Explain.

How many 1-inch square tiles would you use to cover the
rectangle? How do you know?

Neither statement makes sense. Possible explanation: If you
use 10 tiles, some tiles are on top of other tiles.
If you use 6 tiles, there are spaces between the tiles.

eight 1-inch square tiles; Possible answer: I covered the
rectangle with 2 rows of 4 square tiles. My drawing shows that 8
tiles completely cover the rectangle with no spaces or
overlaps.

STEP IT OUT

Les is measuring the area of this figure using unit squares.
Each unit square is 1 square inch. What is the area of the
figure?

STEP IT OUT

Les is measuring the area of this figure using unit squares.
Each unit square is 1 square inch. What is the area of the
figure?

STEP IT OUT

Count the unit squares. You can write the numbers on the
unit squares as you count them. How many unit squares
are in the figure?

What unit of measurement does Les use?

What is the area of the figure?

STEP IT OUT

Count the unit squares. You can write the numbers on the
unit squares as you count them. How many unit squares
are in the figure?

What unit of measurement does Les use?

What is the area of the figure?

6 unit squares

square inch

6 square inches

CHECK UNDERSTANDING

Ula draws this figure. Count to find the area of the figure.
Each unit square is 1 square foot.

Area = _____ square feet

CHECK UNDERSTANDING

Ula draws this figure. Count to find the area of the figure.
Each unit square is 1 square foot.

14
Area = _____ square feet

CHECK UNDERSTANDING

Finn uses unit squares to measure the area of this
figure. What is the area of the figure?

Add. ___________________
Multiply. _______________
Area = _____ square inches

5 + 5 + 5 = 15

3 x 5 = 15

15