Lesson 11: Volume with Fractional Edge Lengths and

Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
6β€’5
Lesson 11: Volume with Fractional Edge Lengths and Unit
Cubes
Student Outcomes

Students extend their understanding of the volume of a right rectangular prism with integer side lengths to right
rectangular prisms with fractional side lengths. They apply the formula 𝑉 = 𝑙 β‹… 𝑀 β‹… β„Ž to find the volume of a
right rectangular prism and use the correct volume units when writing the answer.
Lesson Notes
This lesson builds on the work done in Grade 5, Module 5, Topics A and B. Within these
topics, students determine the volume of rectangular prisms with side lengths that are
whole numbers. Students fill prisms with unit cubes in addition to using the formulas
𝑉 = π‘β„Ž and 𝑉 = 𝑙 β‹… 𝑀 β‹… β„Ž to determine the volume.
Scaffolding:
Students start their work on volume of prisms with fractional lengths so that they can
continue to build an understanding of the units of volume. In addition, they must
continue to build the connection between packing and filling. In the following lessons,
students move from packing the prisms to using the formula.
One way to do this would be to
have students make a
conjecture about how many
cubes will fill the prism, and
then use the cubes to test their
ideas.
The sample activity provided at the end of the lesson will foster an understanding of
volume, especially in students not previously exposed to the Common Core standards.
Classwork
Fluency Exercise (5 minutes): Multiplication of Fractions II
Sprint: Refer to the Sprints and the Sprint Delivery Script sections in the Module Overview
for directions to administer a Sprint.
Use unit cubes to help students
visualize the problems in this
lesson.
Provide different examples of
volume (electronic devices,
loudness of voice), and explain
that although this is the same
word, the context of volume in
this lesson refers to threedimensional figures.
Opening Exercise (3 minutes)
Please note that although scaffolding questions are provided, this Opening Exercise is an excellent chance to let students
work on their own, persevering and making sense of the problem.
Opening Exercise
Which prism will hold more 𝟏 𝐒𝐧. × πŸ 𝐒𝐧. × πŸ 𝐒𝐧. cubes? How many more cubes will the prism hold?
MP.1
πŸ” 𝐒𝐧.
𝟏𝟐 𝐒𝐧.
πŸ’ 𝐒𝐧.
𝟏𝟎 𝐒𝐧.
πŸ“ 𝐒𝐧.
πŸ– 𝐒𝐧.
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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6β€’5
Students discuss their solutions with a partner.

How many 1 in. × 1 in. × 1 in. cubes will fit across the bottom of the first rectangular prism?
οƒΊ

How did you determine this number?
οƒΊ



Both rectangular prisms hold the same number of cubes in one layer, but the second rectangular prism
has more layers.
How many more layers does the second rectangular prism hold?
οƒΊ

The second rectangular prism will hold more cubes.
How did you determine this?
οƒΊ

I will need 12 layers because the prism is 12 in. tall.
Which rectangular prism will hold more cubes?
οƒΊ

40 cubes will fit across the bottom.
How many layers will you need?
οƒΊ
MP.1
There are 6 inches in the height; therefore, 6 layers of cubes will fit inside.
How many 1 in. × 1 in. × 1 in. cubes will fit across the bottom of the second rectangular prism?
οƒΊ

Answers will vary. Students may determine how many cubes will fill the bottom layer of the prism and
then decide how many layers are needed. Students who are English language learners may need a
model of what β€œlayers” means in this context.
How many layers of 1 in. × 1 in. × 1 in. cubes will fit inside the rectangular prism?
οƒΊ

40 cubes will fit across the bottom.
It holds 6 more layers.
How many more cubes does the second rectangular prism hold?
οƒΊ
The second rectangular prism has 6 more layers than the first, with 40 cubes in each layer.
οƒΊ
6 × 40 = 240 more cubes.
What other ways can you determine the volume of a rectangular prism?
οƒΊ
We can also use the formula 𝑉 = 𝑙 βˆ™ 𝑀 βˆ™ β„Ž.
Example 1 (5 minutes)
Example 1
A box with the same dimensions as the prism in the Opening Exercise will be used to ship miniature dice whose side
lengths have been cut in half. The dice are
𝟏
𝟐
𝐒𝐧. ×
𝟏
𝟐
𝐒𝐧. ×
𝟏
𝟐
𝐒𝐧. cubes. How many dice of this size can fit in the box?
Scaffolding:
Students may need a
considerable amount of time to
make sense of cubes with
fractional side lengths.
πŸ” 𝐒𝐧.
πŸ’ 𝐒𝐧.
An additional exercise has been
included at the end of this
lesson to use if needed.
𝟏𝟎 𝐒𝐧.
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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
How many cubes could we fit across the length? The width? The height?
οƒΊ

6β€’5
Two cubes would fit across a 1-inch length. So, I would need to double the lengths to get the number of
cubes. Twenty cubes will fit across the 10-inch length, 8 cubes will fit across the 4-inch width, and 12
cubes will fit across the 6-inch height.
How can you use this information to determine the number of
1
2
in. ×
1
2
in. ×
1
2
in. cubes it will take to fill the
box?

οƒΊ
I can multiply the number of cubes in the length, width, and height.
οƒΊ
20 × 8 × 12 = 1920 of the smaller cubes.
How many of these smaller cubes will fit into the 1 in. × 1 in. × 1 in. cube?
οƒΊ

How does the number of cubes in this example compare to the number of cubes that would be needed in the
Opening Exercise?
οƒΊ
οƒΊ

new
old
1920
240
=
8
1
If I fill the same box with cubes that are half the length, I will need 8 times as many.
1
The volume of the box is of the number of cubes that will fit in it.
8
What is the volume of 1 cube?
οƒΊ
𝑉=
𝑉=

=
How is the volume of the box related to the number of cubes that will fit in it?
οƒΊ

Two will fit across the length, two across the width, and two for the height. 2 × 2 × 2 = 8. Eight
smaller cubes will fit in the larger cube.
1
2
1
8
in. ×
1
2
in. ×
1
2
in.
in3
What is the product of the number of cubes and the volume of the cubes? What does this product represent?
1
οƒΊ
1920 × = 240
οƒΊ
The product represents the volume of the original box.
8
Example 2 (5 minutes)
Example 2
A
𝟏
πŸ’
𝐒𝐧. cube is used to fill the prism.
𝟏
How many 𝐒𝐧. cubes will it take to fill the prism?
πŸ’
πŸ‘
What is the volume of the prism?
πŸ‘
𝐒𝐧.
πŸ’
How is the number of cubes related to the volume?
𝟏 𝐒𝐧.
𝟏
𝟏 𝐒𝐧.
𝟐
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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
6β€’5
How would you determine, or find, the number of cubes that fill the prism?
οƒΊ
One method would be to determine the number of cubes that will fit across the length, width, and
height. Then, I would multiply.
6 will fit across the length, 4 across the width, and 15 across the height.
6 × 4 × 15 = 360 cubes

How are the number of cubes and the volume related?
οƒΊ
The volume is equal to the number of cubes times the volume of one cube.
The volume of one cube is
360 cubes ×

1
64
in3 =
360
64
1
4
in. ×
1
in. ×
4
40
in3 = 5
64
1
4
in. =
1
64
in3 .
5
in3 = 5 in3
8
What other method can be used to determine the volume?
𝑉=π‘™π‘€β„Ž
οƒΊ
1
3
𝑉 = (1 in.) (1 in.) (3 in.)
2
𝑉=
𝑉=

3
in. ×
2
45
8
4
1
1
in. ×
15
4
in.
5
in3 = 5 in3
8
Would any other size cubes fit perfectly inside the prism with no space left over?
οƒΊ
We would not be able to use cubes with side lengths of
1
2
1
2
3
3
1
in., in., or
spaces left over. However, we could use a cube with a side length of
8
in. because there would be
in. without having spaces left
over.
Exercises (20 minutes)
Students will work in pairs.
Exercises
1.
Use the prism to answer the following questions.
a.
Calculate the volume.
𝟏
𝑽 = π’π’˜π’‰
𝟏
𝟐
𝟏
𝑽 = (πŸ“ 𝐜𝐦) ( 𝐜𝐦) (𝟏 𝐜𝐦)
πŸ‘
πŸ‘
πŸ‘
πŸπŸ”
𝟐
πŸ’
𝑽=
𝐜𝐦 × πœπ¦ × πœπ¦
πŸ‘
πŸ‘
πŸ‘
𝑽=
b.
𝟐
𝐜𝐦
πŸ‘
πŸπŸπŸ–
𝟐𝟎
πœπ¦πŸ‘ or πŸ’πŸŽ
πœπ¦πŸ‘
πŸπŸ•
πŸπŸ•
If you have to fill the prism with cubes whose side lengths are less than 𝟏 𝐜𝐦, what size would be best?
The best choice would be a cube with side lengths of
c.
𝟏
πŸ“ 𝐜𝐦
πŸ‘
𝟏
𝐜𝐦
πŸ‘
𝟏
πŸ‘
𝐜𝐦.
How many of the cubes would fit in the prism?
πŸπŸ” × πŸ × πŸ’ = πŸπŸπŸ– cubes
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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d.
Use the relationship between the number of cubes and the volume to prove that your volume calculation is
correct.
The volume of one cube would be
𝟏
πŸ‘
𝐜𝐦 ×
𝟏
πŸ‘
𝐜𝐦 ×
𝟏
πŸ‘
𝐜𝐦 =
Since there are πŸπŸπŸ– cubes, the volume would be πŸπŸπŸ– ×
2.
6β€’5
𝟏
πŸπŸ•
πœπ¦πŸ‘ .
𝟏
πŸπŸπŸ–
𝟐𝟎
πœπ¦πŸ‘ =
πœπ¦πŸ‘ or πŸ’πŸŽ
πœπ¦πŸ‘ .
πŸπŸ•
πŸπŸ•
πŸπŸ•
Calculate the volume of the following rectangular prisms.
a.
𝟏
𝑽 =π’π’˜π’‰
πŸ‘
𝟏
𝟏
𝑽 = (𝟐 𝐜𝐦) ( 𝐜𝐦) (𝟏 𝐜𝐦)
πŸ’
𝟐
πŸ’
𝟏𝟏
𝟏
πŸ“
𝑽=
𝐜𝐦 × πœπ¦ × πœπ¦
πŸ’
𝟐
πŸ’
πŸ“πŸ“
πŸπŸ‘
πŸ‘
𝑽=
𝐜𝐦 or 𝟏
πœπ¦πŸ‘
πŸ‘πŸ
πŸ‘πŸ
𝟏
𝐜𝐦
πŸ’
𝟏
𝐜𝐦
𝟐
πŸ‘
𝟐 𝐜𝐦
πŸ’
b.
πŸ“
πŸ‘
πŸ‘
3.
𝟏
𝐒𝐧.
πŸ‘
𝑽=π’π’˜π’‰
𝟏
𝟏
𝟐
𝑽 = (πŸ‘ 𝐒𝐧.) (πŸ‘ 𝐒𝐧.) (πŸ“ 𝐒𝐧.)
πŸ‘
πŸ‘
πŸ‘
𝟏𝟎
𝟏𝟎
πŸπŸ•
𝑽=
𝐒𝐧. ×
𝐒𝐧. ×
𝐒𝐧.
πŸ‘
πŸ‘
πŸ‘
𝟏, πŸ•πŸŽπŸŽ πŸ‘
πŸπŸ” πŸ‘
𝑽=
𝐒𝐧 or πŸ”πŸ
𝐒𝐧
πŸπŸ•
πŸπŸ•
𝟐
𝐒𝐧.
πŸ‘
𝟏
𝐒𝐧.
πŸ‘
A toy company is packaging its toys to be shipped. Some of the very small toys are placed inside a cube-shaped box
with side lengths of
𝟏
𝐒𝐧. These smaller boxes are then packed into a shipping box with dimensions of
𝟐
𝟏
𝟏
𝟏𝟐 𝐒𝐧. × πŸ’ 𝐒𝐧. × πŸ‘ 𝐒𝐧.
𝟐
𝟐
a.
How many small toys can be packed into the larger box for shipping?
πŸπŸ’ × πŸ— × πŸ• = πŸπŸ“πŸπŸ toys
b.
Use the number of toys that can be shipped in the box to help determine the volume of the box.
One small box would have a volume of
𝟏
𝟐
𝐒𝐧. ×
𝟏
𝟐
𝐒𝐧. ×
𝟏
𝟐
𝐒𝐧. =
𝟏
πŸ–
π’π§πŸ‘ .
Now, I will multiply the number of cubes by the volume of the cube.
πŸπŸ“πŸπŸ ×
𝟏 πŸ‘ πŸπŸ“πŸπŸ πŸ‘
𝐒𝐧 =
𝐒𝐧 = πŸπŸ–πŸ— π’π§πŸ‘
πŸ–
πŸ–
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
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4.
6β€’5
A rectangular prism with a volume of πŸ– cubic units is filled with cubes. First, it is filled with cubes with side lengths
𝟏
𝟏
unit. Then, it is filled with cubes with side lengths of unit.
𝟐
πŸ‘
𝟏
𝟏
a.
How many more of the cubes with -unit side lengths than cubes with -unit side lengths will be needed to
πŸ‘
𝟐
of
fill the prism?
𝟏
𝟐
There are πŸ– cubes with -unit side lengths in 𝟏 cubic unit because the volume of one cube is
𝟏
𝟐
𝟏
cubic units.
πŸ–
Since we have πŸ– cubic units, we would have πŸ– × πŸ– = πŸ”πŸ’ total cubes with -unit side lengths.
𝟏
πŸ‘
There are πŸπŸ• cubes with -unit side lengths in 𝟏 cubic unit because the volume of one cube is
𝟏
πŸ‘
𝟏
cubic units.
πŸπŸ•
Since we have πŸ– cubic units, we would have πŸ– × πŸπŸ• = πŸπŸπŸ” total cubes with -unit side lengths.
πŸπŸπŸ” βˆ’ πŸ”πŸ’ = πŸπŸ“πŸ more cubes
b.
Why does it take more cubes with
𝟏
unit side lengths to fill the prism?
πŸ‘
𝟏
𝟏
𝟏
< . The side length is shorter for the cube with a -unit side length, so it takes more to fill the rectangular
πŸ‘
𝟐
πŸ‘
prism.
5.
Calculate the volume of the rectangular prism. Show two different methods for determining the volume.
Method 1:
𝑽=π’π’˜π’‰
𝟏
πŸ‘
𝟏
𝑽 = (𝟏 𝐦) ( 𝐦) (πŸ’ 𝐦)
𝟐
πŸ’
𝟐
πŸ‘
πŸ‘
πŸ—
𝑽 = ( 𝐦) ( 𝐦) ( 𝐦)
𝟐
πŸ’
𝟐
πŸ–πŸ πŸ‘
𝑽=
𝐦
πŸπŸ”
𝟏
𝑽=πŸ“
π¦πŸ‘
πŸπŸ”
πŸ’
Method 2:
Fill the rectangular prism with cubes that are
The volume of the cubes is
𝟏
πŸ”πŸ’
𝟏
πŸ’
𝐦×
𝟏
πŸ’
𝐦×
𝟏
πŸ’
𝟏
𝟏 𝐦
𝟐
𝐦.
𝟏
𝐦
𝟐
πŸ‘
𝐦
πŸ’
π¦πŸ‘ .
We would have πŸ” cubes across the length, πŸ‘ cubes across the width, and πŸπŸ– cubes across the height.
πŸ” × πŸ‘ × πŸπŸ– = πŸ‘πŸπŸ’ cubes total
πŸ‘πŸπŸ’ cubes ×
𝟏
𝟏
π¦πŸ‘ = πŸ“
π¦πŸ‘
πŸ”πŸ’
πŸπŸ”
Lesson 11:
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Volume with Fractional Edge Lengths and Unit Cubes
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6β€’5
Closing (2 minutes)

When you want to find the volume of a rectangular prism that has sides with fractional lengths, what are some
methods you can use?
οƒΊ
One method to find the volume of a right rectangular prism that has fractional side lengths is to use the
volume formula 𝑉 = π‘™π‘€β„Ž.
οƒΊ
Another method to find the volume is to determine how many cubes of fractional side lengths are inside
the right rectangular prism, and then find the volume of the cube. To determine the volume of the right
rectangular prism, find the product of these two numbers.
Exit Ticket (5 minutes)
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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6β€’5
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
Name
Date
Lesson 11: Volume with Fractional Edge Lengths and Unit Cubes
Exit Ticket
Calculate the volume of the rectangular prism using two different methods. Label your solutions Method 1 and
Method 2.
2
1
Lesson 11:
Date:
3
cm
8
1
cm
4
5
cm
8
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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6β€’5
Exit Ticket Sample Solutions
Calculate the volume of the rectangular prism using two different methods. Label your solutions Method 1 and
Method 2.
Method 1:
𝐕=π₯𝐰𝐑
𝟐
πŸ‘
πŸ“
𝟏
𝐕 = (𝟏 𝐜𝐦) ( 𝐜𝐦) (𝟐 𝐜𝐦)
πŸ–
πŸ–
πŸ’
𝟏𝟏
πŸ“
πŸ—
𝐕=
𝐜𝐦 × πœπ¦ × πœπ¦
πŸ–
πŸ–
πŸ’
πŸ’πŸ—πŸ“
𝐕=
πœπ¦πŸ‘
πŸπŸ“πŸ”
πŸ‘
𝟏 𝐜𝐦
πŸ–
𝟏
𝐜𝐦
πŸ’
πŸ“
𝐜𝐦
πŸ–
Method 2:
Fill shape with
𝟏
πŸ–
𝐜𝐦 cubes.
𝟏𝟏 × πŸ“ × πŸπŸ– = πŸ—πŸ—πŸŽ cubes
Each cube has a volume of
𝐕 = πŸ—πŸ—πŸŽ ×
𝟏
πŸ–
𝐜𝐦 ×
𝟏
πŸ–
𝐜𝐦 ×
𝟏
πŸ–
𝐜𝐦 =
𝟏
πŸ“πŸπŸ
πœπ¦πŸ‘ .
𝟏
πŸ—πŸ—πŸŽ
πŸ’πŸ—πŸ“
πœπ¦πŸ‘ =
πœπ¦πŸ‘ =
πœπ¦πŸ‘
πŸ“πŸπŸ
πŸ“πŸπŸ
πŸπŸ“πŸ”
Problem Set Sample Solutions
1.
Answer the following questions using this rectangular prism:
πŸ’
𝟏
πŸ— 𝐒𝐧.
a.
𝟐
𝐒𝐧.
πŸ‘
𝟏
𝐒𝐧.
πŸ‘
What is the volume of the prism?
𝑽=π’π’˜π’‰
𝟏
𝟐
𝐒𝐧.) (πŸ’ 𝐒𝐧.)
πŸ‘
πŸ‘
πŸ—
πŸ’
πŸπŸ’
𝑽 = ( 𝐒𝐧.) ( 𝐒𝐧.) (
𝐒𝐧.)
𝟏
πŸ‘
πŸ‘
πŸ“πŸŽπŸ’ πŸ‘
𝑽=
𝐒𝐧
πŸ—
𝑽 = πŸ“πŸ” π’π§πŸ‘
𝑽 = (πŸ— 𝐒𝐧.) (𝟏
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
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NYS COMMON CORE MATHEMATICS CURRICULUM
b.
6β€’5
𝟏
πŸ‘
Linda fills the rectangular prism with cubes that have side lengths of 𝐒𝐧. How many cubes does she need to
fill the rectangular prism?
She would need πŸπŸ• across by πŸ’ wide and πŸπŸ’ high.
Number of cubes = πŸπŸ• × πŸ’ × πŸπŸ’
𝟏
πŸ‘
Number of cubes = 𝟏, πŸ“πŸπŸ cubes with 𝐒𝐧. side lengths
c.
How is the number of cubes related to the volume?
πŸ“πŸ” × πŸπŸ• = πŸπŸ“πŸπŸ
The number of cubes needed is πŸπŸ• times larger than the volume.
d.
Why is the number of cubes needed different from the volume?
Because the cubes are not each 𝟏 𝐒𝐧., the volume is different from the number of cubes. However, I could
multiply the number of cubes by the volume of one cube and still get the original volume.
e.
𝟏
𝟐
Should Linda try to fill this rectangular prism with cubes that are 𝐒𝐧. long on each side? Why or why not?
𝟏
πŸ‘
𝟐
πŸ‘
𝟏
𝟐
Because some of the lengths are and some are , it would be difficult to use side lengths of to fill the
prism.
2.
Calculate the volume of the following prisms.
a.
𝑽=π’π’˜π’‰
πŸ’
𝟐
πŸπŸ’ 𝐜𝐦
𝟏
𝐜𝐦
𝟐
𝟐
𝐜𝐦
πŸ‘
𝟐
𝟏
𝐜𝐦) (πŸ’ 𝐜𝐦)
πŸ‘
𝟐
πŸ–
πŸ—
𝑽 = (πŸπŸ’ 𝐜𝐦) ( 𝐜𝐦) ( 𝐜𝐦)
πŸ‘
𝟐
𝟏, πŸ•πŸπŸ–
πŸ‘
𝑽=
𝐜𝐦
πŸ”
𝑽 = πŸπŸ–πŸ– πœπ¦πŸ‘
𝑽 = (πŸπŸ’ 𝐜𝐦) (𝟐
b.
𝟐
πŸ‘
𝐒𝐧.
πŸ’
π’Šπ’
𝟏
πŸ“ 𝐒𝐧.
𝟐
πŸ‘
𝟐
𝐒𝐧.
πŸ“
Lesson 11:
Date:
𝑽=π’π’˜π’‰
𝟐
𝟏
πŸ‘
𝑽 = (πŸ‘ 𝐒𝐧. ) (πŸ“ 𝐒𝐧. ) (𝟐 𝐒𝐧. )
πŸ“
𝟐
πŸ’
πŸπŸ•
𝟏𝟏
𝟏𝟏
𝑽 = ( 𝐒𝐧. ) ( 𝐒𝐧. ) (
𝐒𝐧. )
πŸ“
𝟐
πŸ’
πŸπŸŽπŸ“πŸ• πŸ‘
𝑽=
𝐒𝐧
πŸ’πŸŽ
πŸπŸ• πŸ‘
𝑽 = πŸ“πŸ
𝐒𝐧
πŸ’πŸŽ
Volume with Fractional Edge Lengths and Unit Cubes
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163
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NYS COMMON CORE MATHEMATICS CURRICULUM
3.
A rectangular prism with a volume of 𝟏𝟐 cubic units is filled with cubes. First, it is filled with cubes with
6β€’5
𝟏
unit side
𝟐
𝟏
unit side lengths.
πŸ‘
𝟏
𝟏
How many more of the cubes with unit side lengths than cubes with unit side lengths will be needed to fill
πŸ‘
𝟐
lengths. Then, it is filled with cubes with
a.
the prism?
𝟏
𝟐
There are πŸ– cubes with -unit side lengths in 𝟏 cubic unit because the volume of one cube is
𝟏
𝟐
𝟏
cubic units.
πŸ–
Since we have 𝟏𝟐 cubic units, we would have 𝟏𝟐 × πŸ– = πŸ—πŸ” total cubes with -unit side lengths.
𝟏
πŸ‘
There are πŸπŸ• cubes with -unit side lengths in 𝟏 cubic unit because the volume of one cube is
𝟏
πŸ‘
𝟏
cubic units.
πŸπŸ•
Since we have 𝟏𝟐 cubic units, we would have 𝟏𝟐 × πŸπŸ• = πŸ‘πŸπŸ’ total cubes with -unit side lengths.
πŸ‘πŸπŸ’ βˆ’ πŸ—πŸ” = πŸπŸπŸ– more cubes
b.
Finally, the prism is filled with cubes whose side lengths are
𝟏
𝟏
unit. How many unit cubes would it take to
πŸ’
πŸ’
fill the prism?
𝟏
πŸ’
𝟏
cubic units.
πŸ”πŸ’
𝟏
Since there are 𝟏𝟐 cubic units, we would have 𝟏𝟐 × πŸ”πŸ’ = πŸ•πŸ”πŸ– total cubes with side lengths of unit.
πŸ’
There are πŸ”πŸ’ cubes with -unit side lengths in 𝟏 cubic unit because the volume of one cube is
4.
A toy company is packaging its toys to be shipped. Some of the toys are placed inside a cube-shaped box with side
𝟏
𝟐
𝟏
𝟐
lengths of πŸ‘ 𝐒𝐧. These boxes are then packed into a shipping box with dimensions of πŸπŸ’ 𝐒𝐧. × πŸ• 𝐒𝐧. × πŸ‘ 𝐒𝐧.
a.
How many toys can be packed into the larger box for shipping?
πŸ’ × πŸ × πŸ = πŸ– toys
b.
Use the number of toys that can be shipped in the box to help determine the volume of the box.
𝟏
𝟐
𝟏
𝟐
𝟏
𝟐
πŸ•
πŸ–
One small box would have a volume of πŸ‘ 𝐒𝐧. × πŸ‘ 𝐒𝐧. × πŸ‘ 𝐒𝐧. = πŸ’πŸ π’π§πŸ‘ .
πŸ•
πŸ–
Now, I will multiply the number of cubes by the volume of the cube. πŸ– × πŸ’πŸ π’π§πŸ‘ = πŸ‘πŸ’πŸ‘ π’π§πŸ‘
5.
A rectangular prism has a volume of πŸ‘πŸ’. πŸπŸπŸ’ cubic meters. The height of the box is πŸ‘. 𝟏 meters, and the length is
𝟐. πŸ’ meters.
a.
Write an equation that relates the volume to the length, width, and height. Let π’˜ represent the width, in
meters.
πŸ‘πŸ’. πŸπŸπŸ’ = (πŸ‘. 𝟏)(𝟐. πŸ’)π’˜
b.
Solve the equation.
πŸ‘πŸ’. πŸπŸπŸ’ = πŸ•. πŸ’πŸ’π’˜
π’˜ = πŸ’. πŸ”
The width is πŸ’. πŸ” 𝐦.
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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164
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
6β€’5
Additional Exercise from Scaffolding Box
This is a sample activity that fosters understanding of a cube with fractional edge lengths. It begins with three (two1
1
dimensional) squares with side lengths of 1 unit, unit, and unit, which leads to an understanding of three-dimensional
2
1
1
3
cubes that have edge lengths of 1 unit, unit, and unit.
2

1
How many squares with -unit side lengths will fit in a square with 1 unit side lengths?
2
οƒΊ

3
1
Four squares with -unit side lengths will fit in the square with 1-unit side lengths.
2
1
What does this mean about the area of a square with -unit side lengths?
2
οƒΊ
1
1
2
4
The area of a square with -unit side lengths is of the area of a square with 1-unit side lengths, so it
1
has an area of square units.
4
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM

1
How many squares with side lengths of units will fit in a square with side lengths of 1 unit?
3
οƒΊ

6β€’5
1
Nine squares with side lengths of unit will fit in a square with side lengths of 1 unit.
3
1
What does this mean about the area of a square with -unit side lengths?
3
οƒΊ
1
1
3
9
The area of a square with -unit side lengths is of the area of a square with 1-unit side lengths, so it
1
has an area of square units.
9

Let’s look at what we have seen so far:
Side Length (units)
How many fit into a
unit square?
1
1
1
2
4
1
3
9
Sample questions to pose:

1
Make a prediction about how many squares with -unit side lengths will fit into a unit square; then, draw a
4
picture to justify your prediction.
οƒΊ
16 squares
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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166
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM

6β€’5
1
How could you determine the number of -unit side length squares that would cover a figure with an area of 15
2
1
square units? How many -unit side length squares would cover the same figure?
3
οƒΊ
1
4 squares of -unit side lengths fit in each 1 square unit. So, if there are 15 square units, there will be
2
1
15 × 4 = 60 squares of -unit side lengths.
2
οƒΊ
1
9 squares of -unit side lengths fit in each 1 square unit. So, if there are 15 square units, there will be
3
1
15 × 9 = 135 squares of -unit side lengths.
3
1
1
2
3

Now let’s see what happens when we consider cubes of 1-, -, and -unit side lengths.

How many cubes with -unit side lengths will fit in a cube with 1-unit side lengths?
1
2
οƒΊ
1
Eight of the cubes with -unit side lengths will fit into the cube with a 1-unit side lengths.
2
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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167
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM

6β€’5
1
What does this mean about the volume of a cube with -unit side lengths?
2
οƒΊ
1
1
2
8
The volume of a cube with -unit side lengths is of the volume of a cube with 1-unit side lengths, so it
1
has a volume of cubic units.
8

1
How many cubes with -unit side lengths will fit in a cube with 1-unit side lengths?
3
οƒΊ

1
27 of the cubes with -unit side lengths will fit into the cube with 1-unit side lengths.
3
1
What does this mean about the volume of a cube with -unit side lengths?
3
οƒΊ
1
3
27
The volume of a cube with -unit side lengths is
it has a volume of

1
1
27
of the volume of a square with 1-unit side lengths, so
cubic units.
Let’s look at what we have seen so far:
Side Length (units)
How many fit into a
unit cube?
1
1
1
2
8
1
3
27
Sample questions to pose:

1
Make a prediction about how many cubes with -unit side lengths will fit into a unit cube, and then draw a
4
picture to justify your prediction.
οƒΊ
64 cubes
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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168
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM

6β€’5
1
How could you determine the number of -unit side length cubes that would fill a figure with a volume of 15
2
1
cubic units? How many -unit side length cubes would fill the same figure?
3
οƒΊ
1
8 cubes of -unit side lengths fit in each 1 cubic unit. So, if there are 15 cubic units, there will be 120
2
cubes because 15 × 8 = 120.
οƒΊ
1
27 cubes of -unit side lengths fit in each 1 cubic unit. So, if there are 15 cubic units, there will be 405
3
cubes because 15 × 27 = 405.
Understanding Volume
Volume

Volume is the amount of space inside a three-dimensional figure.

It is measured in cubic units.

It is the number of cubic units needed to fill the inside of the figure.
Cubic Units

Cubic units measure the same on all sides. A cubic centimeter is one centimeter on all sides; a cubic inch is one
inch on all sides, etc.

Cubic units can be shortened using the exponent 3.
6 cubic centimeter = 6 cm3

Different cubic units can be used to measure the volume of space figuresβ€”cubic inches, cubic yards, cubic
centimeters, etc.
Lesson 11:
Date:
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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169
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
6β€’5
Number Correct: ______
Multiplication of Fractions IIβ€”Round 1
Directions: Determine the product of the fractions.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
1 5
×
2 8
3 3
×
4 5
1 7
×
4 8
3 2
×
9 5
5 3
×
8 7
3 4
×
7 9
2 3
×
5 8
4 5
×
9 9
2 5
×
3 7
2 3
×
7 10
3 9
×
4 10
3 2
×
5 9
2 5
×
10 6
5 7
×
8 10
3 7
×
5 9
Lesson 11:
Date:
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
2 3
×
9 8
3 8
×
8 9
3 7
×
4 9
3 10
×
5 13
2 7
1 ×
7 8
1
5
3 ×3
2
6
7
1
1 ×5
8
5
4
2
5 ×3
5
9
2
3
7 ×2
5
8
2
3
4 ×2
3
10
3
1
3 ×6
5
4
7
1
2 ×5
9
3
3
1
4 ×3
8
5
1
2
3 ×5
3
5
2
2 ×7
3
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
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170
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
6β€’5
Multiplication of Fractions IIβ€”Round 1 [KEY]
Directions: Determine the product of the fractions.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
1 5
×
2 8
3 3
×
4 5
1 7
×
4 8
3 2
×
9 5
5 3
×
8 7
3 4
×
7 9
2 3
×
5 8
4 5
×
9 9
2 5
×
3 7
2 3
×
7 10
3 9
×
4 10
3 2
×
5 9
2 5
×
10 6
5 7
×
8 10
3 7
×
5 9
Lesson 11:
Date:
πŸ“
πŸπŸ”
πŸ—
𝟐𝟎
πŸ•
πŸ‘πŸ
πŸ”
πŸ’πŸ“
πŸπŸ“
πŸ“πŸ”
𝟏𝟐
πŸ”πŸ‘
πŸ”
πŸ‘
=
πŸ’πŸŽ 𝟐𝟎
𝟐𝟎
πŸ–πŸ
𝟏𝟎
𝟐𝟏
πŸ”
πŸ‘
=
πŸ•πŸŽ πŸ‘πŸ“
πŸπŸ•
πŸ’πŸŽ
πŸ”
𝟐
=
πŸ’πŸ“ πŸπŸ“
𝟏𝟎 𝟏
=
πŸ”πŸŽ πŸ”
πŸ‘πŸ“
πŸ•
=
πŸ–πŸŽ πŸπŸ”
𝟐𝟏
πŸ•
=
πŸ’πŸ“ πŸπŸ“
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
2 3
×
9 8
3 8
×
8 9
3 7
×
4 9
3 10
×
5 13
2 7
1 ×
7 8
1
5
3 ×3
2
6
7
1
1 ×5
8
5
4
2
5 ×3
5
9
2
3
7 ×2
5
8
2
3
4 ×2
3
10
3
1
3 ×6
5
4
7
1
2 ×5
9
3
3
1
4 ×3
8
5
1
2
3 ×5
3
5
2
2 ×7
3
πŸ”
𝟏
=
πŸ•πŸ 𝟏𝟐
πŸπŸ’ 𝟏
=
πŸ•πŸ πŸ‘
𝟐𝟏
πŸ•
=
πŸ‘πŸ” 𝟏𝟐
πŸ‘πŸŽ
πŸ”
=
πŸ”πŸ“ πŸπŸ‘
πŸ”πŸ‘
𝟏
=𝟏
πŸ“πŸ”
πŸ–
πŸπŸ”πŸ
πŸ“
= πŸπŸ‘
𝟏𝟐
𝟏𝟐
πŸ‘πŸ—πŸŽ
πŸ‘
=πŸ—
πŸ’πŸŽ
πŸ’
πŸ–πŸ’πŸ
πŸ‘πŸ
= πŸπŸ–
πŸ’πŸ“
πŸ’πŸ“
πŸ•πŸŽπŸ‘
πŸπŸ‘
= πŸπŸ•
πŸ’πŸŽ
πŸ’πŸŽ
πŸ‘πŸπŸ
𝟏𝟏
= 𝟏𝟎
πŸ‘πŸŽ
πŸπŸ“
πŸ’πŸ“πŸŽ
𝟏
= 𝟐𝟐
𝟐𝟎
𝟐
πŸ’πŸŽπŸŽ
𝟐𝟐
= πŸπŸ’
πŸπŸ•
πŸπŸ•
πŸ“πŸ”πŸŽ
= πŸπŸ’
πŸ’πŸŽ
πŸπŸ•πŸŽ
= πŸπŸ–
πŸπŸ“
πŸ“πŸ”
𝟐
= πŸπŸ–
πŸ‘
πŸ‘
Volume with Fractional Edge Lengths and Unit Cubes
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171
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
6β€’5
Number Correct: ______
Improvement: ______
Multiplication of Fractions IIβ€”Round 2
Directions: Determine the product of the fractions.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
2 5
×
3 7
1 3
×
4 5
2 2
×
3 5
16.
17.
18.
5 5
×
9 8
5 3
×
8 7
3 7
×
4 8
2 3
×
5 8
3 3
×
4 4
7 3
×
8 10
4 1
×
9 2
6 3
×
11 8
5 9
×
6 10
3 2
×
4 9
4 5
×
11 8
2 9
×
3 10
Lesson 11:
Date:
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
3 2
×
11 9
3 10
×
5 21
4 3
×
9 10
3 4
×
8 5
6
2
×
11 15
2 3
1 ×
3 5
1 3
2 ×
6 4
2
2
1 ×3
5
3
2
1
4 ×1
3
4
1
4
3 ×2
2
5
3
3×5
4
2
1
1 ×3
3
4
3
2 ×3
5
5
1
1 ×3
7
2
1
9
3 ×1
3
10
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
© 2014 Common Core, Inc. Some rights reserved. commoncore.org
This work is licensed under a
Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
172
Lesson 11
NYS COMMON CORE MATHEMATICS CURRICULUM
6β€’5
Multiplication of Fractions IIβ€”Round 2 [KEY]
Directions: Determine the product of the fractions.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
2 5
×
3 7
1 3
×
4 5
2 2
×
3 5
𝟏𝟎
𝟐𝟏
16.
πŸ‘
𝟐𝟎
17.
πŸ’
πŸπŸ“
18.
5 5
×
9 8
5 3
×
8 7
3 7
×
4 8
2 3
×
5 8
3 3
×
4 4
7 3
×
8 10
4 1
×
9 2
6 3
×
11 8
5 9
×
6 10
3 2
×
4 9
4 5
×
11 8
πŸπŸ“
πŸ•πŸ
19.
πŸπŸ“
πŸ“πŸ”
20.
𝟐𝟏
πŸ‘πŸ
21.
πŸ”
πŸ‘
=
πŸ’πŸŽ 𝟐𝟎
22.
πŸ—
πŸπŸ”
23.
𝟐𝟏
πŸ–πŸŽ
24.
πŸ’
𝟐
=
πŸπŸ– πŸ—
25.
πŸπŸ–
πŸ—
=
πŸ–πŸ– πŸ’πŸ’
26.
πŸ’πŸ“ πŸ‘
=
πŸ”πŸŽ πŸ’
27.
πŸ”
𝟏
=
πŸ‘πŸ” πŸ”
28.
𝟐𝟎
πŸ“
=
πŸ–πŸ– 𝟐𝟐
29.
πŸπŸ– πŸ‘
=
πŸ‘πŸŽ πŸ“
30.
2 9
×
3 10
Lesson 11:
Date:
3 2
×
11 9
3 10
×
5 21
4 3
×
9 10
3 4
×
8 5
6
2
×
11 15
2 3
1 ×
3 5
1 3
2 ×
6 4
2
2
1 ×3
5
3
2
1
4 ×1
3
4
1
4
3 ×2
2
5
3
3×5
4
2
1
1 ×3
3
4
3
2 ×3
5
5
1
1 ×3
7
2
1
9
3 ×1
3
10
πŸ”
𝟐
=
πŸ—πŸ— πŸ‘πŸ‘
πŸ‘πŸŽ
𝟐
=
πŸπŸŽπŸ“ πŸ•
𝟏𝟐
𝟐
=
πŸ—πŸŽ πŸπŸ“
𝟏𝟐
πŸ‘
=
πŸ’πŸŽ 𝟏𝟎
𝟏𝟐
πŸ’
=
πŸπŸ”πŸ“ πŸ“πŸ“
πŸπŸ“
=𝟏
πŸπŸ“
πŸ‘πŸ—
πŸπŸ“
πŸ“
=𝟏
=𝟏
πŸπŸ’
πŸπŸ’
πŸ–
πŸ•πŸ•
𝟐
=πŸ“
πŸπŸ“
πŸπŸ“
πŸ•πŸŽ
𝟏𝟎
πŸ“
=πŸ“
=πŸ“
𝟏𝟐
𝟏𝟐
πŸ”
πŸ—πŸ–
πŸ–
πŸ’
=πŸ—
=πŸ—
𝟏𝟎
𝟏𝟎
πŸ“
πŸ”πŸ—
𝟏
= πŸπŸ•
πŸ’
πŸ’
πŸ”πŸ“
πŸ“
=πŸ“
𝟏𝟐
𝟏𝟐
πŸ‘πŸ—
πŸ’
=πŸ•
πŸ“
πŸ“
πŸ–πŸ’
=πŸ”
πŸπŸ’
πŸπŸ—πŸŽ
𝟏𝟎
=πŸ”
πŸ‘πŸŽ
πŸ‘πŸŽ
𝟏
=πŸ”
πŸ‘
Volume with Fractional Edge Lengths and Unit Cubes
2/5/15
© 2014 Common Core, Inc. Some rights reserved. commoncore.org
This work is licensed under a
Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
173