CCSS
G4.MD.3
the area and
formulas
forof
rectangles
in real by
world
MG 1.2
EstimateApply
or determine
theperimeter
area and
volume
solid figures
and mathematical problems. For example, find the width of a rectangular room given the
covering them with squares or by counting the number of cubes
area of the flooring and the length, by viewing the area formula as a multiplication
that
would fillfactor.
them.
equation with
an unknown
UNDERLYING SKILLS AND CONCEPTS:
meaning of area
CCSS G6.G.1
Find the area of right triangles, other triangles, special
quadrilaterals, and polygons by composing into rectangles or decomposing into triangles
and other shapes; apply these techniques in the context of solving real-world and
Find Area of Rectangles and Triangles
You measure area in square units.
a
K
ey Ide
You can multiply to find the area of rectangles and squares.
Count the number of squares in a row.
Count the number of rows.
Multiply rows times squares in a row to find the area.
E x am p l E
1
What is the area of the rectangle?
Count the number of squares in a row.
There are 7 squares in each row.
Count the number of rows.
There are 4 rows.
Then multiply. 7 4 4 7 28
E x am p l E
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The area of the rectangle is 28 square units.
2
What is the area of the square?
What is the area of the triangle?
To find the area of the square,
count the number of squares in
a row and the number of rows.
There are 6 squares in a row.
There are 6 rows.
Multiply to find the area.
6 6 36 square units
The shaded triangle is half of the square.
So the area of the triangle is half the area
of the square, or 18 square units.
You can count shaded squares to check.
page 330
Chapter 28 – Lesson 3
Name
P RAC T I C E
Draw each rectangle. Then find the area.
2. 2 rows of 5 squares
1. 3 rows of 6 squares
18 square units
4. 1 row of 7 squares
C – © CSL Associates, Inc. All rights reserved.
7 square units
10 square units
Math
Reasoning
1 square unit
5. 5 rows of 5 squares
6. 2 rows of 6 squares
25 square units
12 square units
Solve. Show your work.
7. Sara designed a doll’s quilt. She
used 9 rows of squares. There are
7 squares in each row.
How many squares are in the
doll’s quilt?
9 7 63 squares
3. 1 row of 1 square
8. Mrs. Holmes built a picnic
table. It is 3 feet wide and
6 feet long.
What is the area of the
table top?
3 6 18 square feet
Area
MR 2.2
9. Use one-inch grid paper. Make an outline of your hand with your
fingers together. Estimate the area of your hand.
Answers will vary. Have students compare results.
Then have them compare hands to see if those who
computed larger areas actually have larger hands.
Chapter 28 – Lesson 3
page 331
MCX94.HW.CL.G3.FM&Lesson.v211
8/3/04
13:57
Page 222
Name
…at home!
Draw each rectangle. Then find the area.
2. 2 rows of 6 squares
1. 3 rows of 5 squares
15 square units
12 square units
4. 1 row of 6 squares
6 square units
Math
Reasoning
1 square unit
5. 4 rows of 4 squares
6. 2 rows of 7 squares
16 square units
14 square units
Solve. Show your work.
7. Hannah designed a doll’s quilt.
She used 8 rows of squares.
There are 6 squares in each row.
How many squares are in the
doll’s quilt?
8 6 48 squares
3. 1 row of 1 square
8. Mrs. Palm built a picnic table. It
is 3 feet wide and 5 feet long.
What is the area of the
table top?
3 5 15 square feet
Area
MR 2.2
9. Use one-inch grid paper. Make an outline of your foot with your
fingers together. Estimate the area of your foot.
Answers will vary.
page 222
Home Resource and Homework
Chapter 28 Lesson 3
C – © CSL Associates, Inc. All rights reserved.
P RAC T I C E
MCX94TEG3Ch01_32.v8.9.3 2/21/01 14:52 Page 609
Name
P RAC T I C E
Draw each rectangle. Then find the area.
2. 2 rows of 5 squares
1. 3 rows of 6 squares
18 square units
4. 1 row of 7 squares
C – © CSL Associates, Inc. All rights reserved.
7 square units
10 square units
Math
Reasoning
1 square unit
5. 5 rows of 5 squares
6. 2 rows of 6 squares
25 square units
12 square units
Solve. Show your work.
7. Sara designed a doll’s quilt. She
used 9 rows of squares. There are
7 squares in each row.
How many squares are in the
doll’s quilt?
9 7 63 squares
3. 1 row of 1 square
8. Mrs. Holmes built a picnic
table. It is 3 feet wide and
6 feet long.
What is the area of the
table top?
3 6 18 square feet
Area
MR 2.2
9. Use one-inch grid paper. Make an outline of your hand with your
fingers together. Estimate the area of your hand.
Answers will vary. Have students compare results.
Then have them compare hands to see if those who
computed larger areas actually have larger hands.
Chapter 28 – Lesson 3
Student Book Page
page 331
Name
…at home!
Draw each rectangle. Then find the area.
2. 2 rows of 6 squares
1. 3 rows of 5 squares
15 square units
12 square units
4. 1 row of 6 squares
6 square units
Math
Reasoning
1 square unit
5. 4 rows of 4 squares
6. 2 rows of 7 squares
16 square units
14 square units
Solve. Show your work.
7. Hannah designed a doll’s quilt.
She used 8 rows of squares.
There are 6 squares in each row.
How many squares are in the
doll’s quilt?
8 6 48 squares
3. 1 row of 1 square
8. Mrs. Palm built a picnic table. It
is 3 feet wide and 5 feet long.
What is the area of the
table top?
3 5 15 square feet
Area
MR 2.2
9. Use one-inch grid paper. Make an outline of your foot with your
fingers together. Estimate the area of your foot.
Answers will vary.
page 222
Home Resource and Homework
Chapter 28 Lesson 3
C – © CSL Associates, Inc. All rights reserved.
P RAC T I C E