Unit 5 Place Value Patterns And Decimal Operations — Unit Plan

TitleAssessment
Lesson 1
What Is a Thousandth?
Journal Prompt: One Thousandth

What did you learn about 1 thousandth? What do you still wonder about 1 thousandth?

Show Solution
Sample responses: One thousandth can be represented on a grid. It can be written as 0.001. It's really small. It is one tenth of one hundredth. I wonder if there is something smaller than 1 thousandth.
Lesson 2
Thousandths on Diagrams and in Words
Shading Thousandths
  1. Shade the grid to represent 0.149.

  2. What is another way you could represent 0.149?

Diagram, square. Length and width, 1. Partitioned into 10 rows of 10 of the same size squares. No squares shaded.

Show Solution
  1. Sample response:

    Hundredths grid

  2. Sample responses:
    • One tenth, four hundredths, and nine thousandths
    • One hundred forty-nine thousandths
    • 1491,000\frac{149}{1,000}
Lesson 3
Thousandths in Expanded Form
Different Ways to Write a Decimal Number

The shaded region of the diagram shows a number.

  1. Write the number as a decimal.
  2. Write the number as a fraction.
  3. Write the number in expanded form.
  4. Write the number in word form.

Hundredths grids. 57 and nine tenths squares shaded.

Show Solution
  1. 0.579
  2. 5791,000\frac{579}{1,000}
  3. (5×0.1)+(7×0.01)+(9×0.001)\left(5 \times 0.1\right) + \left(7 \times 0.01\right) + \left(9 \times 0.001\right)
  4. five hundred seventy-nine thousandths
Lesson 4
Explore Place Value Relationships
Worth its Weight in Gold

A gold nugget balances with 2 one hundredth ounce weights and 6 one thousandth ounce weights.

  1. What is the weight of the nugget? Write your answer as a decimal.
  2. What is a different set of weights that will balance the nugget? 
Show Solution
  1. 0.026 ounces
  2. Sample response: One hundredth ounce and 16 thousandth ounce weights, because a hundredth is the same as 10 thousandths.
Lesson 5
Compare Decimals
Compare Decimals
Lin threw the disc 5.09 meters. Andre threw the disc 5.1 meters. Who threw the disc farther? Explain or show your reasoning.
Show Solution
Andre. Sample response: They each threw it 5 meters but then 1 tenth is 10 hundredths and that's more than 9 hundredths.
Lesson 6
Compare Decimals on the Number Line
Locate, Label, and Compare Numbers
  1. Locate and label 0.355 and 0.359 on the number line.

    Number line. Eleven evenly spaced tick marks. First tick mark, 35 hundredths. Last tick mark, 36 hundredths.

  2. Which is greater, 0.355 or 0.359? Explain or show your reasoning.
Show Solution
  1. Number line
  2. 0.359 is greater. Sample response: It's farther to the right.
Lesson 7
Round Doubloons
A Golden Dollar

A one-dollar gold coin weighs 1.672 grams.

  1. A scale measures weights to the nearest tenth of a gram. What will the scale read for the weight of this coin?
  2. A different scale measures weights to the nearest hundredth of a gram. What will the scale read for the weight of this coin?
Show Solution
  1. 1.7 grams
  2. 1.67 grams
Lesson 8
Round Decimals
Round to the Nearest Tenth and Hundredth
  1. Round 17.637 to the nearest tenth. Use the number lines if they are helpful.

  2. Round 17.637 to the nearest hundredth. Use the number lines if they are helpful.

    Number line. Eleven evenly spaced tick marks. First tick mark, 17 and 6 tenths. Last tick mark, 17 and 7 tenths. 

    Number line. Eleven evenly spaced tick marks. First tick mark, 17 and 63 hundredths. Last tick mark, 17 and 64 hundredths. 

Show Solution
  1. 17.6
  2. 17.64
Lesson 9
Order Decimals
Order the Decimals
Write these numbers in order from least to greatest: 565.4, 556.040, 565.004
Show Solution
556.040, 565.004, 565.4
Lesson 10
Solve Problems with Decimals
Luge Rider
A luge rider finished a race in 49.256 seconds. Determine the time rounded to the nearest tenth and hundredth of a second.
Show Solution
  • Nearest tenth: 49.3 seconds
  • Nearest hundredth: 49.26 seconds
Section A Check
Section A Checkpoint
Problem 1

Select all representations of 0.631.

A. Six hundred thirty-one hundredths
B.

C.(3×0.1)+(6×0.01)+(1×0.001)(3 \times 0.1) + (6 \times 0.01) +(1 \times 0.001)
D.6311,000\frac{631}{1,000}

E. Six hundred thirty-one thousandths
Show Solution
B, D, E
Problem 2

Order the following decimals from least to greatest.

  • 0.439
  • 0.394
  • 0.441
  • 0.531
  • 0.342

Show Solution

0.342, 0.394, 0.439, 0.441, 0.531

Problem 3

Answer the following questions about rounding 13.728. Explain or show your reasoning. Use the number line if it is helpful.

  1. What is 13.728 rounded to the nearest hundredth
  2. What is 13.728 rounded to the nearest tenth?
Number line. 11 evenly spaced tick marks.
Show Solution
  1. 13.7. Sample response: It is between 13.7 and 13.8 and is closer to 13.7 than to 13.8.
  2. 13.73. Sample response: It is between 13.72 and 13.73 and is closer to 13.73 than to 13.72.
Lesson 11
Make Sense of Decimal Addition
The Value of the Sum

What is the value of 1.20+0.131.20 + 0.13? Explain or show your reasoning.

Show Solution
1.33. Sample responses: 1.20+0.10=1.301.20 + 0.10 = 1.301.30+0.03=1.331.30 + 0.03 = 1.33
Lesson 12
Estimate and Add
Sums of Decimals

Find the value of 3.45+21.63.45 + 21.6. Explain or show your reasoning.

Show Solution

25.05. Sample responses:

  • 21+3=2421+3=24, 0.40+0.60=1.000.40+0.60=1.00, 24+1=2524+1=25, 25+0.05=25.0525+0.05=25.05
  • addition algorithm
Lesson 13
Analyze Addition Mistakes
What is the Error?

The calculation below has an error.

Add. 38 and 7 tenths, plus, 9 and 46 hundredths, equals, 13 and 33 hundredths.

  1. Explain the error.
  2. Find the correct value of 38.7+9.4638.7 + 9.46.
Show Solution
  1. Sample response: The decimal places are not lined up so the 30 in 38.7 is treated like it's only 3.
  2. 48.16. Sample response: 
    Addition algorithm.
Lesson 14
Make Sense of Decimal Subtraction
Subtract

Find the value of 3.571.43.57 - 1.4. Explain or show your reasoning.

Show Solution

2.17. Sample response: 31=23-1=2, 0.570.40=0.170.57-0.40=0.17, 2.00+0.17=2.172.00+0.17=2.17

Lesson 15
Estimate and Subtract
Subtract Decimals

Find the value of 321.8720.4321.87 – 20.4. Explain or show your reasoning.

Show Solution

301.47. Sample responses:

  • 32120=301321 - 20 = 301, 0.80.4=0.40.8 - 0.4 = 0.4, 0.070=0.070.07 - 0 = 0.07, 301+0.4+0.07=301.47301+0.4+0.07=301.47
  •  
    subtraction algorithm

Lesson 16
Addition and Subtraction
Add and Subtract Decimals
  1. Find the value of each expression. Explain or show your reasoning.

    1. 75.24.3775.2 - 4.37
    2. 236.87+5.15236.87 + 5.15
Show Solution
  1. 70.83. Sample response:
    subtraction algorithm
  2. 242.02. Sample response: 236.87+0.13=237236.87+0.13=237, 237+5.02=242.02237+5.02=242.02
Section B Check
Section B Checkpoint
Problem 1

Priya ran 1.9 miles on Saturday, and 2.34 miles on Sunday. How many miles did she run altogether? Explain or show your reasoning.

Show Solution

4.24 miles. Sample response: 1.9+2=3.91.9 + 2 = 3.9, 3.9+0.3=4.23.9 + 0.3 = 4.2, 4.2+0.04=4.244.2 + 0.04 = 4.24

Problem 2

Find the value of each expression. Explain or show your reasoning.

  1. 12.1+5.7712.1 + 5.77

  2. 10.151 - 0.15

  3. 38.1227.338.12 - 27.3
Show Solution
  1. 17.87. Sample response: 12.1+5=17.112.1 + 5 = 17.1, 17.1+0.77=17.8717.1 + 0.77 = 17.87
  2. 0.85. Sample response: 0.15+0.05=0.20.15 + 0.05 = 0.2, 0.2+0.8=10.2 + 0.8 = 1, 0.05+0.8=0.850.05 + 0.8 = 0.85
  3. 10.82. Sample response:
    subtraction algorithm
Lesson 17
Multiply Decimals and Whole Numbers
Multiply a Decimal by a Whole Number

Find the value of each expression. Explain or show your reasoning.

  1. 2×0.42 \times 0.4
  2. 4×0.034 \times 0.03
Show Solution
  1. 0.8. Sample response: 0.4 is 4 tenths and double that is 8 tenths or 0.8.
  2. 0.12. Sample response: 0.03 is 3 hundredths and 4 groups of 3 hundredths is 12 hundredths or 0.12.
Lesson 18
Use Whole Number Facts
Fill in the Blank

Fill in the blank to make each equation true.

  1. 5×0.3=5×3×5 \times 0.3 = 5 \times 3 \times \underline{\hspace{0.9cm}}
  2. 5×0.03=5××0.015 \times 0.03 = 5 \times \underline{\hspace{0.9cm}} \times 0.01
  3. 5×0.03=5 \times 0.03 = \underline{\hspace{0.9cm}}
Show Solution
  1. 0.1
  2. 3
  3. 0.15
     
Lesson 19
Use Properties to Multiply Decimals
Interpret Expressions
  1. Select all the expressions that are equivalent to 15× 0.1915 \times 0.19.

    1. 15×19× 0.0115 \times 19 \times 0.01
    2. (15× 0.1)+(15× 0.09)(15 \times 0.1) + (15 \times 0.09)
    3. 15×19× 0.115 \times 19 \times 0.1
    4. (15× 0.2)(15× 0.01)(15 \times 0.2) - (15 \times 0.01)
  2. Choose one expression to find the value of 15× 0.1915 \times 0.19.
Show Solution
  1. A, B, and D
  2. Sample response: 15×0.215 \times 0.2 is 30 tenths or 3 and 15×0.0115 \times 0.01 is 15 hundredths or 0.15. Then 30.15=2.853 - 0.15 = 2.85.
Lesson 20
Products in the Hundredths Place
Tenths

Find the value of each expression. Use the diagrams if they are helpful.

  1. 0.3×0.60.3 \times 0.6

    2 hundredths grids. No squares shaded on any grids.

  2. 1.3×0.61.3 \times 0.6

    2 hundredths grids. No squares shaded on any grids.

Show Solution
  1. 0.18 (or equivalent)
  2. 0.78 (or equivalent)
Lesson 21
Multiply More Decimals
Why Expressions Have the Same Value
  1. Explain why 2.5×6.42.5 \times 6.4 and (25×64)×0.01(25 \times 64) \times 0.01 have the same value.
  2. Find the value of 2.5×6.42.5 \times 6.4.
Show Solution
  1.  Sample response: 2.5=25×0.12.5 = 25 \times 0.1 and 6.4=64×0.16.4 = 64 \times 0.1 so 2.5×6.4=(25×64)×0.012.5 \times 6.4 = (25 \times 64) \times 0.01
  2. 16. Sample response: 25×64=1,60025 \times 64 = 1,600 so 2.5×6.4=16.002.5 \times 6.4 = 16.00
Section C Check
Section C Checkpoint
Problem 1

Find the value of the expression 0.3×0.50.3 \times 0.5. Explain or show your reasoning. Use the grid if it is helpful.

<p>Diagram, square. Length and width, 1. Partitioned into 10 rows of 10 of the same size squares. No squares shaded. </p>

Show Solution
0.15. Sample response: There are 15 shaded parts and each one is 0.01.

Hundredth grid

Problem 2

To find the value of 0.28×370.28 \times 37 Andre calculates 28×3728 \times 37 and then multiplies by 0.01. Explain or show why Andre's strategy works and use it to find the value of 0.28×370.28 \times 37.

Show Solution

10.36. Sample response: Since 0.28 is 28 hundredths, I can multiply 28 and 37 and then multiply that by 0.01. Since 28×37=1,03628 \times 37 = 1,036, 0.28×370.28 \times 37 is 10.3610.36.

Problem 3
Find the value of the expression 2.1×7.32.1 \times 7.3. Explain or show your reasoning.
Show Solution

15.33. Sample response: I first found 21×7321 \times 73 which is 1,5331,533. Then I multiply that by 0.1 twice since 2.1=21×0.12.1 = 21 \times 0.1 and 7.3=73×0.17.3 = 73 \times 0.1. That gives 15.3315.33.

Lesson 22
Divide Whole Numbers by 0.1 and 0.01
Many Tenths and Hundredths

Find the value of each expression. Explain or show your reasoning.

  1. 7÷0.17 \div 0.1
  2. 7÷0.017 \div 0.01
Show Solution
  1. 70. Sample response: 1÷0.1=101 \div 0.1 = 10 and 7×10=707 \times 10 = 70
  2. 700. Sample response: There are 100 hundredths in 1, so there are 700 hundredths in 7.
Lesson 23
Divide Whole Numbers by Decimals
Divide Whole Numbers by Decimals

Find the value of each expression. Explain or show your reasoning.

  1. 12÷0.512 \div 0.5
  2. 13÷0.0213 \div 0.02
Show Solution
  1. 24. Sample response: There are 2 groups of 0.5 in 1 whole and 12×2=2412 \times 2=24.
  2. 650. Sample responses:
    • There are 50 groups of 0.02 in 1. Since there are 13 wholes, that means there will be 13 times as many 0.02s which is the same as 13 groups of 50.
    • 50×0.02=150 \times 0.02=1500×0.02=10500 \times 0.02 = 10100×0.02=2100\times 0.02=2 and 50×0.02=150 \times 0.02 = 1 so (500+100+50)×0.02=10+2+1=13(500 + 100 + 50) \times 0.02 = 10 + 2 + 1 = 13
Lesson 24
Divide Decimals by Whole Numbers
Divide Decimals by Whole Numbers

Find the value of each expression. Explain or show your reasoning.

  1. 0.9÷30.9 \div 3
  2. 0.09÷30.09 \div 3
  3. 0.8÷50.8 \div 5
Show Solution
  1. 0.3. Sample response: There are 9 tenths so that’s 3 groups of 3 tenths.
  2. 0.03. Sample response: There are 9 hundredths so that’s 3 groups of 3 hundredths.
  3. 0.16. Sample response: There are 80 hundredths so that’s 5 groups of 16 hundredths.
Lesson 25
Divide Decimals by Decimals
Divide by Decimals

Find the value of each expression. Explain or show your reasoning.

  1. 1.6÷0.011.6 \div 0.01
  2. 2.87÷0.012.87 \div 0.01
Show Solution
  • 160. Sample responses: 
    • 1.6÷0.01=160÷11.6 \div 0.01 = 160 \div 1
    • There are one hundred 0.01s in 1, sixty 0.01s in 0.6, and one hundred sixty 0.01s in 1.6.
  • 287. Sample responses:
    • 2.87÷0.01=287÷12.87 \div 0.01 = 287 \div 1
    • There are two hundred 0.01s in 2, eighty 0.01s in 0.8, seven 0.01s in 0.07, and two hundred eighty-seven 0.01s in 2.87.
Lesson 26
Book Fair
No cool-down
Section D Check
Section D Checkpoint
Problem 1

Find the value of 1÷0.051 \div 0.05. Use the diagram if it is helpful.

Diagram, square. Length and width, 1. Partitioned into 10 rows of 10 of the same size squares. No squares shaded.

Show Solution

20. Sample response: I filled in the unit square with groups of 0.05 and there are 20 of them.

Hundredths grid

Problem 2
  1. Explain how the shaded region of the diagram shows 0.72÷60.72 \div 6.
  2. Find the value of 0.72÷60.72\div6.

Diagrams. Square. Partitioned into 10 rows of 10 of the same size squares. 72 squares shaded. For each 12 squares, shading alternates, blue, orange.

Show Solution
  1. Sample response: There is a total of 72 hundredths of the square shaded in the diagram and it is divided into 6 equal groups.
  2. 0.12. Sample response: There are 12 hundredths in each of the groups.
Problem 3

Which expression has the same value as 84÷0.184 \div 0.1?

A.840÷0.01840 \div 0.01
B.840÷10840 \div 10
C.8400÷18400 \div 1
D.8.4÷0.018.4 \div 0.01
Show Solution
8.4÷0.018.4 \div 0.01