## Envision Math Common Core 1st Grade Answers Key Topic 5 Work with Addition and Subtraction Equations

**Essential Question:** How can adding and subtracting help Animals cannot

Find Out Talk to friends and relatives about how animals such as dolphins use sonar. Ask them to help you learn more about sonar in a book or on a computer.

Journal: Make a Book Show what you found out. In your book, also:

- Draw a picture of one way that sonar is used.
- Make up and solve addition and subtraction problems about the animals that use sonar to communicate.

**Review What You Know**

Vocabulary

Question 1.

Circle the addends in the equation.

4 + 5 = 9

Answer:

Addends are nothing but parts of the whole numbers.

Here 4 and 5 are the addends in the given equation

Question 2.

Circle the equation that is a related fact for

10 – 8 = 2.

8 – 6 = 2

8 + 2 = 10

Answer:

Addends are nothing but parts of the whole numbers.

Question 3.

Circle the number that will complete the fact family.

3 + ? = 10

? + 3 = 10

10 – 3 = ?

10 – ? = 3

Answer: 7

**Subtraction Stories**

Use cubes to solve. Write the subtraction equation.

Question 4.

8 squirrels are on the ground. 5 are eating acorns. How many squirrels are NOT eating acorns?

_______ – _______ = ________

Answer:

Given,

8 squirrels are on the ground. 5 are eating acorns.

8 – 5 = 3

Thus 3 squirrels are not eating acorns

Question 5.

Brett has 5 markers. Pablo has 3 markers. How many more markers does Brett have than Pablo?

_______ – _______ = ________

Answer:

Given,

Brett has 5 markers. Pablo has 3 markers.

5 – 3 = 2

Thus Brett has 2 more markers than Pablo.

**Related Facts**

Question 6.

Write the related subtraction facts.

9 = 4 + 5

_______ = _______ – ________

_______ = _______ – ________

Answer:

5 = 9 – 4

4 = 9 – 5

**Pick a Project**

PROJECT 5A

What is growing on that tree?

Project: Make Flash Cards

PROJECT 5B

Does the moon ever change?

Project: Write and Solve Moon Problems

PROJECT 5C

Who captured more pieces?

Project: Play a Game of Checkers

**3-ACT MATH PREVIEW**

Math Modeling

Weighed Down

### Lesson 5.1 Find the Unknown Numbers

**Solve & Share**

Find the missing number in this equation:

7 + _______ = 13

Explain how you found the missing number.

Answer:

Let the missing number x

x = 13 – 7

That means we have to take away 7 from 13.

13 – 7 = 6

7 + 6 = 13

13 – 7 = 6

Thus the missing number is 6.

Visual Learning Bridge

Convince Me! What is the missing number in the equation _______ + 4 = 9? How do you know?

Answer: 5 + 4 = 9

**Guided Practice**

Write the missing numbers. Then draw or cross out counters to show your work.

Question 1.

Question 2.

4 + _______ = 12

Answer: 8

**Independent Practice**

Write the missing numbers. Draw counters to show your work.

Question 3.

_______ – 9 = 8

Answer: 17

Question 4.

_______ = 8 + 3

Answer: 11

Question 5.

_______ + 6 = 12

Answer: 6

Question 6.

8 + _______ = 15

Answer: 7

Question 7.

14 – _______ = 6

Answer: 8

Question 8.

_______ = 11 – 8

Answer: 3

Question 9.

Number Sense Write the missing number to make each equation true.

9 +_______ = 19

_______ – 10 = 9

20 = _______ + 10

_______ – 10 = 10

Answer:

9 +10 = 19

19 – 10 = 9

20 = 10 + 10

20 – 10 = 10

**Problem Solving**

Solve each number story. Write the missing numbers. Use counters if needed.

Question 10.

Reasoning Adam wants to visit 13 states on a road trip. He has visited 7 states so far. How many states does Adam have left to visit?

13 _______ = ________

_________ states

Answer:

Given,

Adam wants to visit 13 states on a road trip. He has visited 7 states so far.

13 – 7 = 6

Adam has left to visit 6 states.

Question 11.

Chelsea needs to make 11 costumes in all for her dance class. She has 4 costumes left to make. How many costumes did Chelsea already make?

11 = _________ _________

__________ costumes

Answer:

Given that,

Chelsea needs to make 11 costumes in all for her dance class.

She has 4 costumes left to make.

11 – 4 = 7

Therefore Chelsea already makes 7 costumes.

Question 12.

Higher Order Thinking Find the missing number in the equation 5 + ___ = 14. Then write a story that matches the problem.

Answer:

5 + _ = 14

5 + x = 14

x = 14 – 5

x = 9

Question 13.

Assessment Practice Match each equation with the correct missing number.

Answer:

### Lesson 5.2 True or False Equations

**Solve & Share**

An equation is true if both sides are equal. Circle the equations that are true. Show why you think so.

Visual Learning Bridge

Convince Me! Is the equation 4 = 11 – 6 true? Explain.

**Guided Practice**

Tell if each equation is True or False. Use the counters to help you.

Question 1.

5 + 2 = 9 – 3

Question 2.

7 = 8 – 1

Answer: True

**Independent Practice**

Tell if each equation is True or False. You can draw counters to help.

Question 3.

5 + 5 = 6 + 4

True

False

Answer:

True

Question 4.

9 = 9 – 1

True

False

Answer: False

Question 5.

3 + 3 = 11 – 8

True

False

Answer: False

Question 6.

13 – 4 = 15 – 6

True

False

Answer: True

Question 7.

7 + 7 = 12 – 5

True

False

Answer: False

Question 8.

10 + 8 = 9 + 9

True

False

Answer: True

Question 9.

7 + 3 = 10 + 2

True

False

Answer: False

Question 10.

6 + 8 = 8 + 6

True

False

Answer: True

Question 11.

4 + 2 = 6 + 1

True

False

Answer: False

**Problem Solving**

Write an equation to show the problem. Fill in the missing numbers. Then tell if the equation is True or False.

Question 12.

Be Precise Shawna has 8 paper airplanes. She gives away 1 plane. Frank has 5 paper airplanes and gets 2 more.

______ – ____ = ______ + _______

True

False

Shawna has _______ planes.

Frank has ________ planes.

Answer:

Given,

Shawna has 8 paper airplanes.

She gives away 1 plane.

Frank has 5 paper airplanes and gets 2 more.

8 – 1 = 7

Thus Shawna has 7 planes.

8 – 1 = 5 + 2

Frank has 5 paper airplanes and gets 2 more.

5 + 2 = 7

Frank has 7 planes.

Thus the equation 8 – 1 = 5 + 2 is true.

Question 13.

**Higher Order Thinking** Can you prove that 4 + 2 = 5 + 1 is true without solving both sides of the equation? Explain.

Answer:

Add 2 more to 4, we get 6

4 + 2 = 6

Now add 1 to 5, we get 6.

5 + 1 = 6

6 = 6

Thus 4 + 2 = 5 + 1

Thus the above equation is true.

Question 14.

**Assessment Practice** Which equations shown below are false? Choose two that apply.

☐ 10 – 3 = 14 – 7

☐ 4 + 3 = 7 + 1

☐ 6 + 6 = 8 + 3

☐ 17 – 8 = 9

Answer: ii, iii are false

### Lesson 5.3 Make True Equations

**Solve & Share**

What number goes in the blank to make the equation true? How do you know?

2 + 5 = ________ + 6

Answer: 2 + 5 = 1 + 6

Visual Learning Bridge

Convince Me! What number can you write in the blank to make this equation true? Use pictures or words to show how you know. 8 + ______ = 6 + 6

Answer: 8 + 4 = 6 + 6

**Guided Practice**

Write the missing numbers to make the equations true. Draw counters to help.

Question 1.

10 + ? = 5 + 7

10 + ? = 12

10 + 2 = 12

Question 2.

9 – 5 = 6 – ?

______ = 6 – ?

_______ = 6 – _______

Answer:

9 – 5 = 6 – ?

4 = 6 – ?

4 = 6 – 2

**Independent Practice**

Write the missing number that makes each equation true.

Question 3.

______ + 6 = 4 + 9

Answer: 7

_ + 6 = 4 + 9

_ + 6 = 13

13 – 6 = 7

Thus you have add to 7 to make the equation true.

Question 4.

14 – 7 = ______ – 3

Answer: 10

14 – 7 = ______ – 3

14 – 7 = 7

7 = _ – 3

7 + 3 = 10

Thus you have to subtract 10 to make the equation true.

Question 5.

8 + ______ = 9 + 4

Answer: 5

8 + ______ = 9 + 4

8 + _ = 13

13 – 8 = 5

Thus you have to add 5 to make the equation true.

Question 6.

10 – ______ = 7 – 3

Answer: 6

10 – ______ = 7 – 3

10 – 4 = 6

Thus you have to subtract 6 to make the equation true.

Question 7.

15 – 10 = 10 – ______

Answer: 5

15 – 10 = 10 – ______

15 – 10 = 10 – 5

5 = 5

Thus you have to subtract 5 to make the equation true.

Question 8.

7 + 4 = 8 + ______

Answer: 3

7 + 4 = 8 + ______

11 = 8 + _

11 – 8 = 3

Thus you have to add 3 to make the equation true.

Question 9.

10 + 2 = ______ + 4

Answer: 8

10 + 2 = ______ + 4

12 = _ + 4

12 – 4 = 8

Thus you have to add 8 to make the equation true.

Question 10.

13 – 10 = ______ – 7

Answer: 10

13 – 10 = ______ – 7

3 = _ – 7

7 + 3 = 10

Thus you have to subtract 10 to make the equation true.

Question 11.

______ + 7 = 9 + 1

Answer: 3

Given

______ + 7 = 9 + 1

_ + 7 = 10

10 – 7 = 3

Thus you have to add 3 to make the equation true.

Question 12.

en Vision® STEM Kari and Chris make “telephones” with paper cups and string. They take a piece of string that is 13 feet long and cut it into two pieces. One piece is 8 feet long. How long is the other piece of string? Write the missing number in the equations.

______ = 13 – 8

13 = ______ + 8

______ feet

Answer:

Given,

They take a piece of string that is 13 feet long and cut it into two pieces.

One piece is 8 feet long.

5 = 13 – 8

13 = 5 + 8

5 feet

Problem Solving

Solve each problem below.

Question 13.

**Reasoning** Kim has 14 tennis balls. Danny has 4 tennis balls. How many more tennis balls does Kim have than Danny?

Answer:

Given,

Kim has 14 tennis balls. Danny has 4 tennis balls.

14 – 4 = 10

Therefore Kim has 10 more tennis balls than Danny.

Question 14.

Ron finds 10 rocks but drops 1 rock. Anson finds 3 rocks. How many more rocks would Anson have to find to have the same number of rocks as Ron?

10 – 1 = 3 + ______

______ more

Answer:

Given,

Ron finds 10 rocks but drops 1 rock. Anson finds 3 rocks.

10 – 1 = 3 + _

9 = 3 + 6

Question 15.

**Higher Order Thinking** José has 5 red crayons and 8 blue crayons. Tasha has 10 red crayons and some blue crayons. If Tasha has the same number of crayons as José, how many blue crayons does she have? Tell how you know.

Answer:

Given,

José has 5 red crayons and 8 blue crayons. Tasha has 10 red crayons and some blue crayons.

8 + 5 = 10 + _

13 = 10 + _

13 = 10 + 3

Thus there are 3 blue crayons.

Question 16.

**Assessment Practice** Draw an arrow to show which number will make the equation true.

1 2 3 4 5 6 7 8 9 10

4 + 7 = 5 + ______

Answer:

4 + 7 = 5 + 6

### Lesson 5.4 Add Three Numbers

**Solve & Share**

Carlos made stacks of 6 books, 4 books, and 6 books. How can you use addition to find the number of books in all three stacks? Write two different equations to show how many books in all.

Visual Learning Bridge

Convince Me! Why can you pick any two numbers to add first when you add three numbers?

**Guided Practice**

Add the circled numbers first. Write their sum in the box. Then write the sum of all three numbers.

Question 1.

Question 2.

Answer:

**Independent Practice**

Circle two numbers to add first. Write their sum in the box at the right. Then write the sum of all three numbers.

Question 3.

Answer:

Question 4.

Answer:

Question 5.

Answer:

Question 6.

Answer:

Question 7.

Answer:

Question 8.

Answer:

Question 9.

Number Sense Help Alex find the missing numbers. The numbers on each branch add up to 15.

Answer:

**Problem Solving**

Write an equation to solve the problem below.

Question 10.

Look for Patterns Maya puts 7 books on a shelf and 3 books on another shelf. Then she puts 5 books on the last shelf. How many books did Maya put on all three shelves?

_______ + _______ = _______

_______ books

Answer:

Given,

Maya puts 7 books on a shelf and 3 books on another shelf.

Then she puts 5 books on the last shelf.

7 + 3 = 10

10 + 5 = 15 books

Therefore Maya put 15 books on all three shelves.

Question 11.

**Higher Order Thinking** Explain how to add 7 + 2 + 3. Use pictures, numbers, or words.

Answer: 7 + 2 + 3 = 12

Question 12.

**Assessment Practice** Ken buys 7 pencils, 6 markers, and 4 pens. He wants to know how many items he bought in all.

Which two numbers can he add first to make a 10?

A. 7 + 6

B. 6 + 4

C. 7 + 4

D. 5 + 4

Answer: B. 6 + 4

### Lesson 5.5 Word Problems with Three Addends

**Solve & Share**

I have 6 oranges, Alex has 2 pears, and Jada has 4 apples. How many pieces of fruit do we have in all?

Write 2 different addition equations to solve the problem.

Visual Learning Bridge

Convince Me! How can grouping numbers in a different way help you to solve a problem?

**Guided Practice**

Write an equation to solve each problem. Choose a way to group the addends.

Question 1.

Tess finds some shells at the beach. She finds 7 pink shells, 3 black shells, and 4 white shells. How many shells does Tess find in all?

Question 2.

Tom sees some birds. He sees 4 red birds, 2 blue birds, and 6 black birds. How many birds does Tom see in all?

______ + ________ + _______ = _________

_______ birds

Answer:

Given that,

Tom sees some birds. He sees 4 red birds, 2 blue birds, and 6 black birds.

Add all the number of birds

4 + 2 + 6 = 12

Thus there are 12 birds in all.

Hence Tom sees 12 birds in all.

**Independent Practice**

Write an equation to solve each problem. Choose a way to group the addends.

Question 3.

Pat has sports cards. He has 8 baseball cards, 2 football cards, and 3 basketball cards.

How many cards does Pat have in all?

______ + ______ + ______ = ______

______ cards

Answer:

Given data,

Pat has sports cards. He has 8 baseball cards, 2 football cards, and 3 basketball cards.

8 + 2 + 3 = 10 + 3 = 13 cards

Thus Pat has 13 cards in all.

Question 4.

Bob plants seeds. He plants 2 brown seeds, 6 white seeds, and 8 black seeds.

How many seeds does Bob plant in all?

______ + ______ + ______ = ______

______ seeds

Answer:

Given,

Bob plants seeds. He plants 2 brown seeds, 6 white seeds, and 8 black seeds.

2 + 6 + 8 = 16 seeds

Thus Bob plant 16 seeds in all.

Write the missing numbers for each problem.

Question 5.

Algebra 16 = 7 + ______ + 6

Answer:

Given,

16 = 7 + ______ + 6

Let the missing number be x.

16 = 7 + x + 6

16 = 13 + x

x = 16 – 13

x = 3

Thus the missing number is 3.

Question 6.

Algebra 11 = 2 + 2 + ______

Answer:

Let the missing number be x.

11 = 2 + 2 + ______

11 = 4 + x

x = 11 – 4

x = 7

Thus the missing number is 7.

Question 7.

Vocabulary Julio finds 3 ladybugs and some ants. Then he finds 5 beetles. Julio finds 14 bugs in all. How many ants did Julio find? Write the missing addend.

14 = 3 + ______ + 5

Julio found ______ ants.

Answer:

Given,

Vocabulary Julio finds 3 ladybugs and some ants. Then he finds 5 beetles. Julio finds 14 bugs in all.

14 = 3 + _ + 5

14 = 8 + x

x = 14 – 8

x = 6

Julio found 6 ants.

Question 8.

Higher Order Thinking Rosa picks 12 flowers from her garden. She picks some purple flowers. Then she picks 4 pink flowers and 3 yellow flowers. How many purple flowers did Rosa pick?

12 = ? + 4 + 3

Rosa picked _________ purple flowers.

Answer:

Given,

Rosa picks 12 flowers from her garden. She picks some purple flowers.

Then she picks 4 pink flowers and 3 yellow flowers.

12 = ? + 4 + 3

12 = ? + 7

The missing number is 7.

Rosa picked 7 purple flowers.

**Problem Solving**

Solve each problem below.

Question 9.

Generalize Dan throws 3 beanbags at the target. The numbers on the target show the score for each beanbag. Write an addition equation to find Dan’s score.

______ + ______ + ______ = ______

Answer:

3 + 5 + 7 = 15

Question 10.

**Higher Order Thinking** Write a storyproblem about toys. The story should match the addition equation below. 4 + 1 + 9 = 14

Answer:

Question 11.

**Assessment Practice** Joy throws 3 beanbags at the target. She scores 17 points. Which picture shows her target?

Answer: A

### Lesson 5.6 Solve Addition and Subtraction Word Problems

**Solve & Share**

José has 5 more erasers than Lois. José has 7 erasers. How many erasers does Lois have? Write your answers below.

Visual Learning Bridge

Convince Me! Tom made 8 fewer sandcastles than Tina. Tina made 10 sandcastles. How many sandcastles did Tom make?

**Guided Practice**

Use the model to solve the problem.

Question 1.

Sal has 8 more magazines than Gemma. Sal has 15 magazines. How many magazines does Gemma have?

Gemma has ________ magazines.

Answer:

Given that,

Sal has 8 more magazines than Gemma. Sal has 15 magazines.

15 – 8 = 7

8 + 7 = 15

Therefore Gemma has 15 magazines.

**Independent Practice**

Use the models to complete the problems. 2. Alan picks up 3 toys.

Question 2.

Alan picks up 3 toys. Then he picks up 8 more. How many toys did Alan pick up in all?

______ + _______ = ________

Alan picked up ________ toys in all.

Answer:

Given,

Alan picks up 3 toys. Then he picks up 8 more.

3 + 8 = 11

Therefore Alan picked up 11 toys in all.

Question 3.

Jack makes 5 fewer fruit cups. than Sandi. Sandi makes 11 fruit cups. How many fruit cups did Jack make?

________ – _________ = _________

Jack made _________ fruit cups.

Answer:

Given,

Jack makes 5 fewer fruit cups. than Sandi. Sandi makes 11 fruit cups.

11 – 5 = 6

Thus Jack made 6 fruit cups.

Fill in the missing numbers for the model and the equation. Choose addition or subtraction to solve.

Question 4.

Harry has 5 fewer buttons than Tina. Harry has 7 buttons. How many buttons does Tina have?

________ _______ = ________

_______ buttons

Answer:

Given,

Harry has 5 fewer buttons than Tina. Harry has 7 buttons.

7 – 5 = 2

Thus Tina has 2 buttons.

Question 5.

Mark calls some people. Jane calls 8 people. They called 17 people in all. How many people did Mark call?

________ _______ = ________

_______ people

Answer:

Given,

Mark calls some people. Jane calls 8 people. They called 17 people in all.

17 – 8 = 9

Thus Mark call 9 people.

**Problem Solving**

Solve the problems below.

Question 6.

Make Sense Ashlyn had some grapes. She gives 5 grapes to Anna. Now Ashlyn has 7 grapes. How many grapes did Ashlyn have before?

________ _______ = ________

Ashlyn had _________ grapes before.

Answer:

Given that,

Ashlyn had some grapes. She gives 5 grapes to Anna. Now Ashlyn has 7 grapes.

5 + 7 = 12

Thus Ashlyn had 12 grapes before.

Question 7.

Make Sense Lucy and Tim find 15 bottle caps together. Tim finds 7 of the bottle caps. How many of the bottle caps does Lucy find?

________ _______ = ________

Lucy finds _________ bottle caps.

Answer:

Given,

Lucy and Tim find 15 bottle caps together.

Tim finds 7 of the bottle caps.

15 – 7 = 8

Therefore Lucy finds 8 bottle caps.

Question 8.

**Higher Order Thinking** Draw a model to show the equation. Then write and solve the equation.

16 – 10= ?

_______ – ________ = _______

Answer: 16 – 10 = 6

Question 9.

**Assessment Practice** Tanner has 3 more pets than Ava. Tanner has 7 pets. How many pets does Ava have? Use the models to solve the problem.

Ava has ________ pets

Answer:

Given,

Tanner has 3 more pets than Ava. Tanner has 7 pets.

Thus Ava has 4 pets

### Lesson 5.7 Problem Solving

Precision

**Solve & Share**

Write a true equation with one number on one side and three numbers on the other side. Each number should be different. Explain your reasoning.

_______ + _______ = _________

Answer: 1 + 3 = 4

Thinking Habits Am I using numbers and symbols correctly? Is my answer clear?

Visual Learning Bridge

Convince Me! Is the equation below true or false? How do you know? 10 + 5 = 9 + 3 + 3

**Guided Practice**

Write the symbol (+, -, or =) or number to make the equation true. Then tell how you know you found the correct symbol or number.

Question 1.

3 + 8 = 4 +

Question 2.

4 + 3 + ☐ = 13

Answer: 6

Explanation:

Let the missing number be x.

4 + 3 + x = 13

7 + x = 13

x = 13 – 7

x = 6

Thus the missing number is 6.

**Independent Practice**

Write the symbol (+, -, or =) or number to make the equation true. Then tell how you know you found the correct symbol or number.

Question 3.

19 10 = 9

Answer: –

19 – 10 = 9

The correct symbol is ‘-‘

Question 4.

20 = ☐ + 5 + 5

Answer: 10

20 = ☐ + 5 + 5

20 – 10 = ☐

☐ = 10

Thus the missing number is 10.

Question 5.

10 + 1 6 + 5

Answer: =

10 + 1 = 11

6 + 5 = 11

Therefore 10 + 1 = 6 + 5

Question 6.

9 – 2 = 10 3

Answer: –

9 – 2 = 7

10 – 3 = 7

Thus 9 – 2 = 10 – 3

Question 7.

Algebra Write the missing number in the equation below. Explain how you know.

42 + 55 = 55 + ☐

Answer: 42

42 + 55 = 55 + 42

**Problem Solving**

Performance Task Balloon Party Dani has 7 green and 4 yellow balloons. Gene has 15 blue balloons.

Question 8.

Explain If Gene gives 4 of his balloons away, then he and Dani will have the same number. Fill in the blanks to make the equation true. Use +, -, or =.

7 4 15 4

Explain how you chose the symbols.

_____________________

_____________________

How do you know the equation is true?

Answer:

7 + 4 = 15 – 4

7 + 4 = 11

15 – 4 = 11

Thys the true equation is 7 + 4 = 15 – 4.

Question 9.

Be Precise If Gene keeps all 15 blue balloons, how many balloons would Dani need to buy to have the same number as Gene? Complete the equation to find the answer.

7 4 _______ 15

Did you use numbers and symbols correctly? Explain how you know.

Answer: 4

7 + 4 = _ + 15

15 – 11 = 4

### Topic 5 Fluency Practice Activity

Point & Tally

Find a partner. Get paper and a pencil. Each partner chooses a different color: light blue or dark blue. Partner I and Partner 2 each point to a black number at the same time. Subtract Partner I’s number from Partner 2’s number. If the answer is on your color, you get a tally mark. Work until one partner gets twelve tally marks.

### Topic 5 Vocabulary Review

Understand Vocabulary

Question 1.

Circle True or False for the addition equation below.

4 + 6 = 5 + 2 + 3

True

False

Answer: True

Explanation:

4 + 6 = 10

5 + 2 + 3 = 10

Thus the given equation is true.

Question 2.

Circle True or False for the subtraction equation below.

10 = 11 – 2

True

False

Answer: False

Explanation:

11 – 2 = 9

10 ≠ 9

Thus the given equation is False.

Question 3.

Write the number you need to add to make the equation true.

7 – 3 = 2 + ________

Answer: 2

Given,

7 – 3 = 2 + ________

7 – 3 = 4

4 = 2 + 2

Thus you need to add 2 to make the equation true.

Question 4.

Write the number you need to add to make the equation true.

_______ + 4 + 2 = 10

Answer: 4

Given,

_______ + 4 + 2 = 10

_ + 6 = 10

10 – 6 = 4

Thus you need to add 4 to make the equation true.

Question 5.

Write the number you need to subtract to make the equation true.

9 = 10 – _______

Answer: 1

10 – 1 = 9

Thus you need to subtract 1 to make the equation true.

Use Vocabulary in Writing

Question 6.

Write a story problem with a true equation.

Use at least two words from the Word List.

### Topic 5 Reteaching

**Set A**

Solve to find out if the equation is True or False.

6 + 5 = 3 + 8

Solve one side first. 6 + 5 = 11

Solve the other side. 3 + 8 = 11

11 = 11

This equation is True.

Tell whether each equation is True or False.

Question 1.

8 – 5 = 4 + 1

True

False

Answer: False

8 – 5 = 3

4 + 1 = 5

3 ≠ 5

Thus the given equation is false.

Question 2.

3 + 1 = 12 – 8

True

False

Answer: True

3 + 1 = 12 – 8

3 + 1 = 4

12 – 8 = 4

Thus the given equation is True.

**Set B**

Write the missing numbers to make the equations true.

4 + 7 = 6 + _______

Both sides should be equal.

4 + 7 = 11

So, 6 + 5 = 11.

The missing number is 5.

4 + 7 = 6 + 5

Find and write the missing numbers to make the equations true.

Question 3.

11 = _______ + 4

Answer:

11 – 4 = 7

Thus the missing number is 7

That means you have to add 7 to make the equations true.

Question 4.

_______ – 4 = 5

Answer:

5 + 4 = 9

Thus the missing number is 9

That means you have to subtract 9 to make the equations true.

Question 5.

10 + 5 = 6 + _______

Answer:

10 + 5 = 15

15 – 6 = 9

Thus the missing number is 9.

That means you have to add 9 to make the equations true.

Question 6.

9 – _______ = 13 – 10

Answer:

13 – 10 = 3

9 – 6 = 3

Thus the missing number is 6.

That means you have to subtract 6 to make the equations true.

Question 7.

14 – _______ = 2 + 2

Answer:

2 + 2 = 4

14 – 10 = 4

Thus the missing number is 10.

That means you have to subtract 10 to make the equations true.

**Set C**

You can add three numbers in any order.

2 + 8 + 2 = ?

Make a 10. Then add 2.

Find the sum. Solve in any order.

Question 8.

5 + 5 + 4 = ________

Answer:

Given,

5 + 5 + 4 = ________

5 + 5 = 10

10 + 4 = 14

Question 9.

9 + 5 + 1 = ________

Answer:

9 + 5 + 1 = ________

9 + 1 = 10

10 + 5 = 15

Question 10.

6 + 4 + 4 = _________

Answer:

6 + 4 + 4 = _________

6 + 4 = 10

10 + 4 = 14

Question 11.

3 + 3 + 5 = ________

Answer:

3 + 3 + 5 = ________

3 + 3 = 6

6 + 5 = 11

**Set D**

Write the symbol (+, -, or =) or number to make the equation true. Then tell how you know you chose the correct symbol or number.

Question 12.

10 – 5 = 2 3

Answer:

10 – 5 = 5

2 + 3 = 5

So, the correct symbol is ‘+’

Question 13.

4 + 5 = 10 1

Answer:

4 + 5 = 9

10 – 1 = 9

So, the correct symbol is ‘-‘

### Topic 5 Assessment Practice

Question 1.

A. Complete the model. Then write the missing number in the equation.

14 = _______ + 9

Answer:

14 – 9 = 5

Thus the missing number in the equation is 5.

B. The sum in the equation has increased by 3 to give 17 = ☐ + 9. What is the missing number?

17 = _____ + 9

Answer:

17 = ☐ + 9

17 – 9 = ☐

☐ = 8

Thus the missing number is 8.

Question 2.

A. Which number is missing?

16 – ? = 2 + 6

A. 10

B. 9

C. 8

D. 7

Answer: C. 8

Explanation:

Given,

16 – ? = 2 + 6

16 – ? = 8

16 – 8 = ?

? = 8

Therefore the missing number is 8.

The correct answer is option C.

B. Write the missing numbers to make each equation true.

16 – _____ = 2 + 7

16 – _____ = 2 + 8

16 – _____= 2 + 9

Answer:

16 – _____ = 2 + 7

16 – _ = 9

16 – 9 = 7

Thus we have to subtract 7 to make the equation true.

16 – _____ = 2 + 8

16 – _ = 10

16 – 10 = 6

Thus we have to subtract 10 to make the equation true.

16 – _____= 2 + 9

16 – _ = 11

16 – 11 = 5

The missing number is 5.

Thus we have to subtract 5 to make the equation true.

Question 3.

Tell if the equation is True or False.

4 + 7 = 13 – 3

True

False

Answer: False

Explanation:

4 + 7 = 11

13 – 3 = 10

11 ≠ 10

Thus the equation is false.

Question 4.

Tasha has 2 dogs and 3 cats. How many more pets does Tasha need if she wants a total of 11 pets?

________ more pets

Answer:

Given,

Tasha has 2 dogs and 3 cats.

2 + 3 = 5 pets

If she wants a total of 11 pets

11 – 5 = 6

then she needs to have more 6 pets.

Question 5.

Bill has 10 apples. He uses 8 of them to make muffins. Josh has 6 apples. How many should he use so he has the same number as Bill?

10 – 8 = 6 – _________

_________ apples

Answer: 4

Explanation:

Given,

Bill has 10 apples.

He uses 8 of them to make muffins.

Josh has 6 apples.

10 – 8 = 6 – _

2 = 6 – _

6 – 2 = _

_ = 4

Therefore he should use 4 apples.

Question 6.

Kerry, Tom, and Nicole want to play tennis. Kerry has 5 tennis balls. Tom has 5 tennis balls. How many tennis balls does Nicole have if they have 13 tennis balls in all?

A. 3

B. 4

C. 5

D. 6

Answer: 3

Explanation:

Given,

Kerry, Tom, and Nicole want to play tennis.

Kerry has 5 tennis balls. Tom has 5 tennis balls.

5 + 5 = 13 – _

10 = 13 – _

13 – 10 = 3

Thus the correct answer is option A.

Question 7.

In a soccer game, Andrew scores 3 fewer goals than Elsie. Elsie scores 9 goals. How many goals did Andrew score? Complete the bar diagram and write an equation to match the story.

_________goals

Answer: 6 goals

Explanation:

In a soccer game, Andrew scores 3 fewer goals than Elsie. Elsie scores 9 goals.

9 – 3 = 6 goals

Question 8.

Write the missing symbol (+, -, or =) to make the equation true. Use precise math language to explain how you chose the symbol.

16 = 4 + 8 4

Answer:

16 = 4 + 8 + 4

The correct symbol is ‘+’

### Topic 5 Performance Task

A Vase of Flowers

Terry and his brother, Dave, put flowers in a vase for their mother.

Question 1.

Complete the equation below to show the number of lilies and roses. Use numbers and symbols (+, -, =).

____ + 5 _______

Answer:

From the above figure we can see that there are 8 lilies and 5 roses.

The total number of lilies and roses are 8 + 5 = 13

Thus the correct symbol is 13.

Question 2.

How many roses, daisies, and carnations are in the vase?

Write an equation to solve.

____ + ____ + ____ = ____

Explain how you added. Use pictures, numbers, or words.

Answer:

From the above figure we can see that there are 5 roses, 5 daisies and 2 carnations

5 + 5 + 2 =11

Question 3.

Terry puts the roses and the daisies in the vase. Dave puts the carnations and the lilies in the vase. Did they put an equal number of flowers in the vase?

Complete the equation.

____ + ___ = ____ + ____

Fill in the missing numbers.

Terry puts ____ flowers in the vase.

Dave puts ____ flowers in the vase.

Did Terry and Dave each put an equal number of flowers in the vase? Circle Yes or No.

Yes

No

Answer:

Given,

Terry puts the roses and the daisies in the vase.

From the above figure we can see that there are 5 roses, 5 daisies

5 + 5

Dave puts the carnations and the lilies in the vase.

From the above figure we can see that there are 2 carnations and 8 lilies

2 + 8 = 10

The equation would be 5 + 5 = 2 + 8

So, the answer is yes.

Question 4.

Dave says there are 3 more daisies than carnations. What equation can he use to find out if he is right?

5 _______ ________

Answer:

Given,

Dave says there are 3 more daisies than carnations.

5 = 3 + 2

Question 5.

Terry says that if there were 2 fewer lilies, then the number of lilies would be equal to the number of daisies. He writes the equation below. Is this equation true or false? Explain how you know.

8 – 2 = 5

Answer:

Given,

Terry says that if there were 2 fewer lilies, then the number of lilies would be equal to the number of daisies

8 – 2 = 6 not 5

So, the equation is false.

Question 6.

Terry and Dave buy more carnations. Now they have 10 in all. How many carnations did they buy? Complete the equation using +, -, or=.

10 2 8 ________ more carnations

Use precise math language to explain how you chose the symbols.

Answer:

Given,

Terry and Dave buy more carnations. Now they have 10 in all.

10 = 2 + 8