FIFTH GRADE
3RD SIX WEEKS
WEEK 2
MULTIPLYING DECIMALS
E
TEKS
3E, 3D
PL
Reporting Category
2
SA
M
Vocabulary:
Multiply
Decimal point
Decimal place
Place value
Product
Factors
Array
Whole numbers
Hundredths
Tenths
Ones
ACTIVITY 1
Materials:
Base ten blocks
Paper and pencil
1.
Whole Number × Decimal
Using models to multiply decimals Write this problem on the board:
3 × 1.2 = _____
This problem says:
3 groups of 1 and 2 tenths.
3 groups. 1 and 2 tenths in each group.
How many in all?
PY
Say:
T
=
C
O
Build 3 groups of 1 and 2 tenths. Then combine bocks to solve -
Why did I put the decimal point in this position in the product?
Discuss how the blocks match the product.
N
Say:
O
Work the problem for the students.
O
How is multiplying decimals like multiplying whole numbers?
How is it different?
The problem you will solve says:
D
Say:
2 groups of 1 and 4 tenths
2 groups. 1 and 4 tenths in each group.
How many in all?
Instruct students to build 2 groups of 1 and 4 tenths.
=
Fifth Grade Mathematics Curriculum
3rd Six Weeks: Week 2, Multiplying Decimals
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Page 1
ACTIVITY 2
Materials:
Base ten blocks
Paper and pencil
1.
Decimal × Decimal
Using models to multiply decimals Write this problem on the board
0.3 × 1.2 = _____
This problem says:
What is 3 tenths of a group of 1 and 2 tenths?
Build 1 and 2 tenths.
C
O
Divide 1 and 2 tenths into 10 equal groups.
PY
Say:
=
T
To find 3 tenths, we take 3 of the 10 groups.
What is the value of 3 groups?
Why did I put the decimal point in this position in the product?
Discuss how the blocks match the product.
N
Say:
O
Work the problem for the students.
O
How is multiplying decimals like multiplying whole numbers?
How is it different?
Write the problem on the board :
2.3 × 1.1 = _____
This problem says:
D
Say:
What is 2 and 3 tenths and 1 and 1 tenth.
Build 2 and 3 tenths.
To show 1 and 1 tenth, we will use our one whole.
Fifth Grade Mathematics Curriculum
3rd Six Weeks: Week 2, Multiplying Decimals
'
1 whole
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Page 3
How do we show 1 tenth? (Remember we are working
with multiplication, so our model must form a
rectangular array.)
Add 1 tenth to the model.
Combine the blocks to solve:
PY
'
Work the problem for the students.
2 . 3
× 1 . 1
C
O
2 3
% 2 3 0
2 . 5 3
Repeat this process with other examples:
T
2.
0.2 × 0.4 = 0.08
Three decimal places in product
0.3 × 0.33 = .099 0.4 × 0.02 = .008 0.7 × 0.12 = .084
O
Two decimal places in product
0.4 × 2.2 = 0.88
0.6 × 1.3 = 0.78
Intensify Instruction (not tested)
0.4 × 1.7 = 0.68
0.5 × 2.1 = 1.05
0.8 × 0.3 = .24
Have students develop the rule for multiplying a decimal by a decimal.
Multiply as though you were multiplying with whole numbers.
Count the total number of decimal places in the factors (to the right of the decimal) and place the
decimal point this number of places in the final product.
D
O
3.
N
Three decimal places in product
Fifth Grade Mathematics Curriculum
3rd Six Weeks: Week 2, Multiplying Decimals
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Page 4
ACTIVITY 4
Materials:
Blackline Master:
Pencils
Paper
Multiplying Decimals
Multiplying Decimals 4 (2 pages)
9.1 × 6.5 = 59.15
B
6.3 × 8.5 = 53.55
C
3.1 × 1.5 = 4.65
D
2.1 × 0.5 = 1.05
E
7.9 × 0.3 = 2.37
C
O
A
PY
Write these problems on the board to review with students. Create word problems as you solve each
problem
T
Practice: Multiplying Decimals 4, 1 - 10
16.59
6
7.2 kg
2
7.68
7
12.6
3
5.7
8
36.52
4
11.85
9
$3.4
5
$15.75
10
$2.10
D
O
N
O
1
Fifth Grade Mathematics Curriculum
3rd Six Weeks: Week 2, Multiplying Decimals
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Page 6
WEEK 2 ASSESSMENT
Answer Key RC
A
2
7
G
2
8
9 360.14 2
J
2
10
TEKS
3E/1B
3E/1B
3K/1B
3K/1B
Answer Key
C
11
H
12
RC
2
2
TEKS
3K/1B
3K/1B
N
O
Assessment
Answer Key
RC TEKS
0.32
2
3D
1
H
2
3E
2
B
2
3D/1C
3
0.56
2
3E/1C
4
B
2
3E
5
H
2
3E/1B
6
Critical Thinking Question
Cues and Activities:
C
O
TEKS
3D/1B
3E/1B
3E/1B
T
Test Taking Skills
Answer Key
RC
B
2
1
H
2
2
B
2
3
PY
RC TEKS
2 3D
Represent multiplication of decimals with products to the hundredths using objects and
pictorial models, including area models
2 3E
Solve for products of decimals to the hundredths, including situations involving money, using
strategies based on place value understandings, properties of operations, and her relationship to
the multiplication of whole numbers
2 3K
Add and subtract positive rational numbers fluently
PS 1B
Use a problem-solving model that incorporates analyzing given information, formulating a
plan or strategy, determining a solution, justifying the solution and evaluating the problemsolving process and the reasonableness of the solution
PS 1C
Select tools, including real objects, manipulatives, paper and pencil and technology as
appropriate and techniques including mental math, estimation and number sense as appropriate
to solve the problem
O
Question Cues:
C How is multiplying decimals like/unlike multiplying whole numbers?
How does the position of the decimal point...?
D
C
Activities:
C Have students cut out advertisements of items with prices including dollars and cents to be used in
creating original word problems for multiplication of decimals.
C
Show 3 different ways to solve 3 × 0.08.
Fifth Grade: 3rd Six Weeks, Week 2 Assessment
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
WEEK 2 ASSESSMENT
STUDENT PERFORMANCE DATA
Student Name
Item Number
Reporting Category
TEKS
1
2
3D
2
2
3E
3
2
3D/
1C
4
2
3E/
1C
5
2
3E
6
2
3E
/1B
7
2
3E/
1B
8
2
3E/
1B
9
2
3K/
1B
10
2
3K/
1B
11
2
3K/
1B
12
2
3K/
1B
1
2
3
PY
4
5
6
7
C
O
8
9
10
11
12
13
14
T
15
16
O
17
18
20
21
22
N
19
O
23
24
D
25
Fifth Grade: 3rd Six Weeks, Week 2 Assessment
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name ______________________________________
Week 2 Assessment
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Fifth Grade: 3rd Six Weeks, Week 2 Assessment
9
•
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1
Assessment
PY
Test Taking Skills
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© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name _______________________________________
Gina has some coins in her shirt pocket. The
model shows the amount she had. Her sister Gari
has three times as many coins as Gina. How much
money did Gari have?
C
O
A
B
C
D
$12.90
$1.29
$14.90
$1.11
O
Michelle can hold her breath for 0.41 minutes. Her
friend Diego can hold his breath 2 times as long.
How long can Diego hold his breath?
F
0.43 minutes
G
4.03 minutes
H
0.82 minutes
J
8.2 minutes
D
O
2
$3.64
$0.49
$0.42
$4.90
T
A
B
C
D
3
PY
Kamila bought 3.5 pounds of nuts. Each pound
costs $0.14. How much did Kamila pay for the
nuts?
N
1
Week 2 Test Taking Skills
Fifth Grade: 3rd Six Weeks, Week 2 Assessment
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name _______________________________________
1
What is the product of 2 and 0.16?
Use the decimal model to solve.
Week 2 Assessment, Page 1
3
Look at the multiplication model below.
Which expression does the model represent?
B
Record your answer and fill in the bubbles on your
answer document. Be sure to use the correct place
value.
C
2.3 × 1.1
2.5 × 3
Not Here
C
O
D
230 × 2.3
PY
A
4
$1.38
G
$0.73
H
$2.76
J
$27.06
Use a picture or sketch to represent the expression
4 × 0.14. Then find the product.
Record your answer and fill in the bubbles on your
answer document. Be sure to use the correct place
value.
N
F
O
T
Karley needs curling ribbon that costs $0.69 a
foot. She needs to buy 4 feet of ribbon. How much
will Karley pay for the ribbon?
D
O
2
Fifth Grade: 3rd Six Weeks, Week 2 Assessment
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name _______________________________________
14.4 lbs
C
1.32 lbs
D
7.4 lbs
PY
B
C
O
13.2 lbs
T
A
F
37.5
G
3.75
H
1.56
J
Not Here
O
Justin and his mother are baking muffins for his class. Their recipe calls for 1.25 cups of water. Justin needs to
triple the recipe in order to make enough for his entire class. How many cups of water will they use?
D
O
8
Mr. Mater weighed his 3 puppies. Each puppy weighed an average of 4.4 lbs. How much did all 3 puppies
weigh?
N
7
Week 2 Assessment, Page 3
Fifth Grade: 3rd Six Weeks, Week 2 Assessment
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name _______________________________________
Davian’s rabbit had 4 babies. He made a table of
the baby rabbits' weights.
9
Week 2 Assessment, Page 4
11
Cecilia measured the volume of 4 different jars
and recorded the information in the table below.
Weight of Rabbits
Weight (in grams)
Jar
Volume (in mL)
A
93.4
A
7.08
B
87
B
8.2
C
86.6
C
0.94
D
93.14
PY
Rabbit
D
6.35
What was the weight of Davian’s four rabbits?
Which is the volume in all 4 jars?
Record your answer and fill in the bubbles on your
answer document. Be sure to use the correct place
value.
A
B
C
D
225.70 mL
33.51 mL
22.57 mL
19.47 mL
C
O
A school cafeteria purchased 242.8 pounds of
beans in September. The table below shows the
number of pounds of beans used in 3 weeks.
12
T
10
Volume
O
Pounds of Beans
Week 1
39.75
Week 2
22.5
Week 3
31.85
Mr. Collins used 2,300 feet of pipe to repair the
sprinkler systems in 3 city parks. He used 482 feet
of pipe in the first park and 937 feet in the second
park. How many feet of pipe did he use to repair
the sprinkler system in the third park?
F
G
H
J
919 ft
1,891 ft
881 ft
1,119 ft
180.55 lb
140.77 lb
94.1 lb
Not here
D
O
F
G
H
J
N
After these 3 weeks, how many pounds of beans
did the cafeteria have?
Fifth Grade: 3rd Six Weeks, Week 2 Assessment
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name _______________________________________
Multiplying Decimals 4, Page 1
Write the number sentence in the grid and solve for each product.
2.1 × 7.9 =
3
9.5 × 0.6 =
6.4 × 1.2 =
4
7.9 × 1.5
N
×
D
O
×
O
T
2
×
C
O
×
PY
1
Fifth Grade: 3rd Six Weeks, Week 2, Multiplying Decimals
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015
Name _________________________________
Multiplying Decimals 4, Page 2
Jaden makes $2.50 an hour volunteering at an animal shelter. If he works 6.3 hours, how much will he
earn?
6
Carmen’s cat weighs 3.6 kilograms. Her dog weights 2 times as much. How much does her dog weigh?
7
Mr. Rovan measured 3 plants in his vegetable garden. Each one was 4.2 inches tall. How many inches
tall were the 3 plants combined?
8
Kelley rides her bike to and from school. If the distance she rides is 9.13 kilometers, how many
kilometers will she ride in 4 days?
9
Marvin bought 5 goldfish. Each goldfish cost $0.68. How much did Marvin spend?
D
O
N
O
T
C
O
PY
5
10
A concession stand sells popcorn for $0.35 per bag. Jake and 5 of his friends each bought a bag of
popcorn. How much did they spend on popcorn?
Fifth Grade: 3rd Six Weeks, Week 2, Multiplying Decimals
© Sharon Wells Mathematics Curriculum, Inc. 2014 - 2015