## Envision Math Common Core 1st Grade Answers Key Topic 10 Use Models and Strategies to Add Tens and Ones

**enVision STEM Project: Watch the Stars**

**Find Out** Talk to friends and relatives about stars. Discuss why the stars you see in the sky change from night to night.

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

- Draw the stars you can see from where you live.
- Make up and solve addition problems about the stars.

**Review What You Know**

**Vocabulary**

Question 1.

Circle the digit that shows how many ones.

91

Answer:

Question 2.

Circle the digit that shows how many tens.

13

Answer:

Question 3.

Circle the symbol that tells you add.

+ – =

Answer:

**Understanding Addition**

Question 4.

Write an addition equation to match the picture.

Answer:

Question 5.

Noah mows 7 lawns. Mari mows 13 lawns. How many lawns did the two friends mow in all? Write an addition equation to solve.

__ + __ = ____

Answer:

**Hundred Chart**

Question 6.

Fill in the missing numbers on the part of the hundred chart.

Answer:

**pick a Project**

**PROJECT 10A**

Has anyone ever called you the wrong name?

Project: Make a Manatee Facts Book

**PROJECT 10B**

Have you ever aimed at a target?

Project: Play a Target Toss Game

**PROJECT 10C**

What is as colorful as a butterfly?

Project: Make a Leaf and Egg Model

**PROJECT 10D**

What would life be like without bones?

Project: Write and Draw an Octopus Story

### Lesson 10.1 Add Tens Using Models

**Solve & Share**

How are these addition problems alike? Talk to a partner about how you can use the first sum to help you find the second.

**Visual Learning Bridge**

**Convince Me!**

How is adding 6 + 3 like adding 60 + 30?

**Guided Practice**

Write the numbers to complete each equation.

Question 1.

Answer:

Question 2.

Answer:

**Independent Practice**

Write the numbers to complete each equation.

Question 3.

Answer:

Question 4.

Answer:

Question 5.

Answer:

Question 6.

Answer:

Question 7.

Answer:

Question 8.

Answer:

Question 9.

Answer:

Question 10.

Answer:

Question 11.

Answer:

**Problem Solving**

Add tens to solve. Use place-value blocks if needed.

Question 12.

**Make Sense** Alex and Annie each have 5 boxes of crayons. Each box has 10 crayons.

How many crayons do Alex and Annie have in all?

___ + ___ = ___

___ crayons

Answer:

Question 13.

**Make Sense** Becky and Dan buy some bottles of juice. Becky buys 6 bottles. Dan buys 2 bottles. Each bottle of juice is enough for 10 people. How many people do Dan and Becky have enough juice for?

___ + __ = ___

___ people

Answer:

Question 14.

**Higher Order Thinking** Bree says that she knows 4 + 3 = 7, so she also knows that 30 + 40 = 70. Is she correct? Explain how you know.

Answer:

Question 15.

**Assessment Practice** Which equation matches the picture?

A. 2 + 3 = 5

B. 3 + 2 = 5

C. 20+ 3 = 23

D. 20 + 30 = 50

Answer:

### Lesson 10.2 Mental Math: Ten More Than a Number

**Solve & Share**

Solve each problem. What pattern do you see in the totals?

**Visual Learning Bridge**

**Convince Me!**

Explain how you can use mental math to add 10 to 47.

**Guided Practice**

Use mental math to solve the problems.

Question 1.

Answer:

Question 2.

Answer:

**Independent Practice**

Use mental math to solve each equation.

Question 3.

58 + 10 = ___

Answer:

Question 4.

44 + 10 = ___

Answer:

Question 5.

35 + 10 = ___

Answer:

Question 6.

10 + 72 = ___

Answer:

Question 7.

87 + 10 = ___

Answer:

Question 8.

31 + 10 = ___

Answer:

Question 9.

18 + 10 = ___

Answer:

Question 10.

10 + 26 = ___

Answer:

Question 11.

9 + 10 = ___

Answer:

Question 12.

**Number Sense** Winnie used place-value blocks to show 29 + 10. She said the answer is 30. Is Winnie correct? Explain how you know.

Answer:

**Problem Solving**

Use mental math to solve the problems below.

Question 13.

**Reasoning** Sam makes 15 dollars mowing lawns one day. He makes 10 dollars the next day. How many dollars did Sam make in all?

____ dollars

Answer:

Question 14.

**Reasoning** Tess solves 22 math problems. Then she solves 10 more math problems. How many math problems did Tess solve in all?

___ math problems

Answer:

Question 15.

**Higher Order Thinking** Roger collects 75 cans. Ella collects some cans. Roger and Ella have 85 cans together. How many cans did Ella collect?

___ cans

Question 16.

**Assessment Practice** Match each pair of addends with their sum.

Answer:

### Lesson 10.3 Add Tens and Ones Using a Hundred Chart

**Solve & Share**

Use a hundred chart to find these sums. 8 + 40 = ? 30 + 40 = ? 80 + 12 = ?

Show your work and tell how you found each sum.

**Visual Learning Bridge**

**Convince Me!**

How could you use the hundred chart to find the sum of 6 and 50?

**Guided Practice**

Use the part of the hundred chart to add.

Question 1.

2 + 12 = __14__

Question 2.

5 + 40 = ___

Answer:

Question 3.

13 + 20 = ___

Answer:

Question 4.

10 + 31 = ___

Answer:

Question 5.

32 + 6 = ___

**Independent Practice**

Use the hundred chart to add.

Question 6.

7 + 60 = ____

Answer:

Question 7.

33 + 20 = ___

Answer:

Question 8.

20 + 18 = ___

Answer:

Question 9.

5 + 13 = ___

Answer:

Question 10.

3 + 26 = ___

Answer:

Question 11.

1 + 41 = ___

Answer:

Question 12.

4 + 32 = ___

Answer:

Question 13.

56 + 2 = ___

Answer:

Question 14.

10 + 85 = __

Answer:

Question 15.

7 + 12 = ___

Answer:

Question 16.

50 + 13 = ___

Answer:

Question 17.

71 + 5 = ___

Answer:

Question 18.

**Higher Order Thinking** Sue had some stickers in a book. She bought 30 more stickers. Now she has 36 stickers in her book. How many stickers did Sue have in the book at the start?

_____ stickers

**Problem Solving**

Use the hundred chart to solve each problem below.

Question 19.

**Use Tools** Some hens lay 40 eggs. Then they lay 45 more eggs. How many eggs did the hens lay in all?

___ eggs

Answer:

Question 20.

**Use Tools** 22 students are at the book fair. More students came to the book fair later. There are 72 students in all at the book fair. How many students came later?

____ students

Answer:

Question 21.

**Higher Order Thinking** Write a number story for 3 + 42.

Answer:

Question 22.

**Assessment Practice** Use the hundred chart. Which equations show the correct sum for 50 + 8? Choose two that apply.

8 + 50 = 85

50 + 8 = 13

8 + 50 = 58

50 + 8 = 58

### Lesson 10.4 Add Tens and Ones Using an Open Number LineName

**Solve & Share**

Use the open number lines to find the sums.

43 + 6 = ? 5+ 19 = ? 10+ 32 = ?

**Visual Learning Bridge**

**Convince Me!**

Think about the problem 20 + 17. Would it be easier to start with 20 or 17 on the number line to solve the problem?

**Guided Practice**

Add using the number lines.

Question 1.

Answer:

Question 2.

Answer:

Question 3.

11 + 8 = ___

Answer:

Question 4.

40 + 16 = ___

Answer:

Question 5.

48 + 20 = ___

Answer:

Question 6.

22 + 7 = ___

Answer:

Question 7.

**Higher Order Thinking** Write an addition equation using a two-digit and one-digit number. Then solve by showing your work on the number line.

Answer:

**Problem Solving**

Solve the problems below.

Question 8.

**Use Tools** Danny writes 20 pages of his paper on Monday. He writes 32 pages on Tuesday. How many pages did Danny write in all? Use the number line to solve.

20 + 32 = ___ ___ pages

Answer:

Question 9.

**Use Tools** Last year, Leah watched 41 movies. This year, she has watched 30 movies. How many movies has Leah watched in all? Use the number line to solve.

41 + 30 = ___ ___ movies

Question 10.

**Higher Order Thinking** Explain how you would solve 57 + 7 on a number line.

Answer:

Question 11.

**Assessment Practice**

Add 60 + 26 on a number line. Show your work.

60 + 26 = ___

Answer:

### Lesson 10.5 Add Tens and Ones Using Models

**Solve & Share**

Maddy has 50 stickers. Jill gives Maddy 5 more stickers. Use place-value blocks to show how many stickers Maddy has now. Then use numbers and pictures to show your work.

**Visual Learning Bridge**

**Convince Me!**

Could you count on by 10s to add 21 + 20?

**Guided Practice**

Use blocks to add. Then draw what you did.

Question 1.

Answer:

Question 2.

16 + 30 = __

Answer:

Question 3.

32 + 20 = ___

Answer:

Question 4.

33 + 6 = ___

Answer:

**Independent Practice**

Add. Draw blocks to show your work.

Question 5.

37 + 2 = ___

Answer:

Question 6.

21 + 40 = ___

Answer:

Question 7.

42 + 10 = ___

Answer:

Question 8.

4 + 33 = ___

Answer:

Question 9.

50 + 14 = ___

Answer:

Look for a pattern to help you find the missing numbers.

Question 10.

**Algebra** Write the missing numbers. Then write the last addition problem in the pattern.

Answer:

**Problem Solving**

Write an equation to solve each problem below. Use blocks to help if needed.

Question 11.

**Model** Jamal has 32 coins in his piggy bank. Jamal’s dad gives him 4 more coins. How many coins does Jamal have now?

___ + ___ = ___

__ coins

Answer:

Question 12.

**Model** Julie sells 18 muffins on Monday. She sells 20 muffins on Friday. How many muffins did Julie sell in all?

___ + __ = ___

___ muffins

Answer:

Question 13.

**Higher Order Thinking** Jake has 9 marbles. He gets some more marbles. Now Jake has 79 marbles. How many marbles did Jake get? Draw a picture to solve.

Answer:

Question 14.

**Assessment Practice** Which is the sum for 40 + 37?

A 47

B 57

C 67

D 77

Answer:

### Lesson 10.6 Make a Ten to Add

**Solve & Share**

What strategy can you use to find 8 + 5?

How can you use the sum for 8 + 5 to help you find 28 + 5? Show your work and be ready to explain your thinking.

**Visual Learning Bridge**

**Convince Me!**

When you add two numbers, how do you know if you can make a 10?

**Guided Practice**

Draw blocks and make a 10 to add.

Question 1.

Find 37 + 7.

Answer:

**Independent Practice**

Draw blocks and make a 10 to add.

Question 2.

17 + 7

Think: 17 + ___ = 20

So, break apart 7 into ___ + ___.

20 + ___ = ___

So, 17 + 7 = ___

Answer:

Question 3.

38 +4

Think: 38 + ___ = 40

So, break apart 4 into __ + ___

40 + ___ = ___

So, 38 + 4 = __

Question 4.

42 + 8 = ___

Answer:

Question 5.

29 +5 = ___

Answer:

**Algebra** Write each missing number. Use place-value blocks if you need to.

Question 6.

23 + = 32

Answer:

Question 7.

35 + = 40

Answer:

**Problem Solving**

Solve each problem below.

Question 8.

**Model** Jamie has 28 cards. His sister gives him 6 more cards. How many cards does Jamie have now? Draw blocks to show your work.

__ cards

Answer:

Question 9.

**Model** Lisa knits 15 scarves. Then she knits 8 more. How many scarves does Lisa knit in all? Draw blocks to show your work.

cards

___ scarves

Answer:

Question 10.

**Higher Order Thinking** Explain how to find 19 + 6. Use equations to show your thinking.

Answer:

Question 11.

**Assessment Practice** Explain how to use the make a 10 strategy to find 37 + 5.

Answer:

### Lesson 10.7 Add Using Place Value

**Solve & Share**

Grace is solving 35 + 8. First she adds 35 + 5 = 40. What should she do next to find the answer? Draw a model to explain.

**Visual Learning Bridge**

**Convince Me!**

Do you need to make a 10 to add 23 + 15? How do you know?

**Guided Practice**

Add. Draw blocks to help.

Question 1.

Find 36 + 24.

6 + 4 = __10__

30 + 20 = ___

So, 36 + 24 = ___

Answer:

Question 2.

Find 19 + 25.

9 + 5 = __14__

10 + 20 = __30__

So, 19 + 25 = ___

Answer:

**Independent Practice**

Add. Draw blocks or an open number line to help./

Question 3.

Find 19 + 42.

9 + 2 = ___

10 + 40 = ___

19 + 42 = ___

Answer:

Question 4.

Find 27 + 25.

7 + 5 = ___

20 + 20 = ___

27 + 25 = ___

Answer:

Add. You can draw blocks or an open number line to help.

Question 5.

37 + 33 = ___

Answer:

Question 6.

28 + 44 = ___

Question 7.

25 + 26 = ___

Answer:

Question 8.

56 + 33 = ___

Answer:

**Problem Solving**

Solve. You can draw blocks or an open number line to help you.

Question 9.

**Reasoning** Sara mows 15 lawns. Bill mows 12 lawns. How many lawns did they mow in all? Write an addition equation to show the problem.

__ lawns

Answer:

Question 10.

**Reasoning** Jon reads 24 pages. Then he reads 27 more pages. How many pages does he read in all? Write an addition equation to show the problem.

___ pages

Answer:

Question 11.

**Higher Order Thinking** Explain how to find 27 + 15 by adding the tens first. Use equations to show your thinking.

Answer:

Question 12.

**Assessment Practice** For which addition equations can you make a 10 to add? Choose two that apply.

12 + 29 = __?__

61 +26 = __?__

33 + 35 = __?__

34 + 18 = __?__

### Lesson 10.8 Practice Adding Using Strategies

**Solve & Share**

A puzzle has 59 green pieces and 25 orange pieces. Solve 59 + 25 to find how many pieces in all. Use any of the strategies you have learned.

**Visual Learning Bridge**

**Convince Me!**

Why can you use different strategies to solve the same problem?

**Guided Practice**

Find each sum. Solve any way you choose. Draw or explain what you did.

Question 1.

37 + 24 = __61__

Answer:

Question 2.

48 + 10 = ___

Answer:

**Independent Practice**

Find each sum. Solve any way you choose. Draw or explain what you did.

Question 3.

Answer:

Question 4.

Answer:

Question 5.

Answer:

Question 6.

Answer:

**Problem Solving**

Find each sum. Solve any way you choose.

Question 7.

**Reasoning** Lilly makes necklaces. She has 43 blue beads. She has 20 pink beads. How many beads does Lilly have in all?

___ beads

Answer:

Question 8.

**Reasoning** Jay has a hat collection. He has 27 hats from football teams. He has 33 hats from baseball teams. How many hats does Jay have in all?

___ hats

Answer:

Question 9.

**Higher Order Thinking** Connie’s soccer team has a bake sale. The team sells 18 banana muffins and 24 oat muffins. They sell 12 granola bars. How many muffins did Connie’s team sell? Draw a picture and write an equation to show your work.

___ muffins

Answer:

Question 10.

**Assessment Practice** Garret uses place-value blocks to show 53 + 18. Which of the following model this problem? Choose two that apply.

Answer:

### Lesson 10.9 Model with Math

**Solve & Share**

Pam has 13 buttons. Julie gives her some more. Now Pam as 30 buttons. Use blocks or a number line to figure out how many buttons Julie gave Pam.

**Thinking Habits**

How can I use numbers and symbols to solve this problem? How can I use the math I know to show this problem?

**Visual Learning Bridge**

**Convince Me!**

If Miko has 23 green marbles and 30 blue marbles, how many marbles does he have in all? Draw a picture to solve the problem.

**Guided Practice**

Use drawings to show and solve the problem. Then write the equation.

Question 1.

Ellen has 27 stickers. Her brother gives her 26 stickers. How many stickers does Ellen have in all?

___ + ___= ___

Answer:

**Independent Practice**

Use drawings to show and solve the problem. Then write the equation.

Question 2.

Barry has 12 red cars. He has 14 blue cars. How many cars does Barry have in all?

___ + ___ = ___ cars

Answer:

Question 3.

Amy picks 18 roses. Roger picks 36 tulips. How many flowers do Amy and Roger pick in all?

___ + ___ = ___ flowers

Answer:

Question 4.

There are 16 apples in the bowl. George buys 15 more apples. How many apples are there in all?

__ + ___ = __ apples

**Problem Solving**

**Performance Task**

**Stamp Collection**

Manuel, Matt, and Jessica each have their own stamp collection.

Question 5.

**Model** Manuel has 18 stamps. Matt gives Manuel 30 stamps. Now how many stamps does Manuel have in all? Draw a picture to show the problem.

Answer:

Question 6.

**Model** Write an equation that matches the story.

Answer:

Question 7.

**Explain** Matt has 24 red stamps. He asks Jessica for enough red stamps to make 50 red stamps. Jessica gives him 25 red stamps. Did Jessica give Matt enough red stamps? Explain how you know using words or pictures.

Can you make a 10? Why or why not.

Answer:

### Topic 10 Fluency Practice

Color these sums and differences. Leave the rest white.

**Topic 10 Vocabulary Review**

**Understand Vocabulary**

Question 1.

Use the models to add the tens.

___ tens + ___ tens = ___ tens

Answer:

Question 2.

Use the models to add the tens.

___ tens + ___ tens = ___ tens

Answer:

Question 3.

Find 19 + 12.

Add the ones. 9 + 2 = ___

Then add the tens. 10 + 10 = ___

Draw blocks to help. 19 + 12 = ___

Answer:

**Use Vocabulary in Writing**

Question 4.

Solve 20 + 6 using an open number line. Explain how you solved it using terms from the Word List.

Answer:

### Topic 10 Reteaching

**Set A**

You can add groups of 10.

Write the numbers to complete each equation.

Question 1.

Answer:

Question 2.

Answer:

**Set B**

You can also use mental math to add 10. When you add 10, the tens digit goes up by 1. The ones digit stays the same.

Answer:

Use mental math to solve the problems below.

Question 3.

36 + 10 = ___

Answer:

Question 4.

53 + 10 = ___

Answer:

Question 5.

71 + 10 = ___

Answer:

**Set C**

You can use part of a hundred chart to add tens and ones.

3+ 40 = ?

Use the part of the hundred chart to add tens and ones.

Question 6.

4 + 50 = ___

Answer:

Question 7.

8 + 30 = ___

Answer:

**Set D**

You can use an open number line to add.

Use an open number line to add.

Question 8.

11 + 6 = ___

Answer:

**Set E**

You can use blocks to add tens to a number.

Add the tens and the ones. Use blocks to help you.

Question 9.

44 + 30 = ___

Answer:

Question 10.

20 + 5 = ___

Answer:

Question 11.

30 + 28 = ___

Answer:

Question 12.

19 + 60 = ___

**Set F**

Sometimes you can make 10 when you add.

Draw blocks and make a 10 to add.

Question 13.

33 + 9

Think: 33 + __ = 40

So, break apart 9 into ___ + ___.

40 + __ = ___

So, 33 + 9 = ___

**Set G**

You can draw blocks to help you add. First add the ones. Then add the tens.

There are 4 tens and 3 ones. 24 + 19 = 43

Add. Draw blocks to help.

Question 14.

Find 67 + 16.

7 + 6 = ___

60 + 10 = ___

67 + 16 = ___

Answer:

**Set H**

**Thinking Habits**

**Model with Math**

Can I use a drawing, diagram, table, or graph to model the problem? Can I write an equation to show the problem?

Use drawings to show and solve the problem. Then write the equation.

Question 15.

Sally sees 15 birds. Then she sees 17 more. How many birds did Sally see in all?

___ + ___ = ___

Answer:

### Topic 10 Assessment Practice

Question 1.

Write an equation that matches the place-value blocks below.

Answer:

Question 2.

Find the sum. Draw place-value blocks to show how you found it. 50 + 3 = ___

Answer:

Question 3.

Find the sum of 16 and 18.

Use words, pictures, or a model to solve. Write the equation.

Answer:

Question 4.

Which equation matches the place-value blocks shown below? Choose two that apply.

Answer:

60 + 30 = 90

6 tens + 3 tens = 9 tens

60 + 10 = 70

4 tens + 3 tens = 7 tens

6 tens + 3 ones = 9 ones

Answer:

Question 5.

Find the sum of 18 and 11. Explain how you solved the problem. Did you need to make a 10?

Answer:

Question 6.

Solve the problem.

Use place-value blocks if needed. 28 + 13 = Can you make a 10? Explain.

Circle Yes or No.

Question 7.

Use the part of the hundred chart to add. Choose the possible explanation for how to find 46 + 20.

A. I start at 46 and then move two rows up to get 26. So, 46 + 20 = 26.

B. I start at 46 and then move one row down and four columns to the right to get 60. So, 46 + 20 = 60.

C. I start at 46 and then move two rows down to get 66. So, 46 + 20 = 66.

D. I start at 46 and then move two rows down to get 68. So, 46 + 20 = 68.

Answer:

Use the part of the hundred chart to solve each problem. What is one way to explain your answer?

Question 8.

10 + 27 = ?

A. 17; I started at 27 and subtracted 1 ten.

B. 28; I started at 27 and added 1 ten.

C. 37; I started at 27 and added 1 ten.

D. 40; I started at 10 and added 3 tens.

Answer:

Question 9.

4 + 35 = ?

A. 95; I started at 35 and added 4 tens.

B. 39; I started at 35 and added 4 ones.

C. 31; I started at 35 and subtracted 4 ones.

D. 12; I started at 32 and subtracted 2 tens.

Use mental math to solve. Then explain how you found your answer.

Question 10.

53 + 10 = ___

Answer:

Question 11.

48 + 10 = ___

Answer:

Question 12.

64 + 10 = ___

Answer:

Find the correct number to complete each equation.

Question 13.

20 + 70 = ___

Answer:

Question 14.

30 + ___ = 60

Answer:

Question 15.

__ + 20 = 40

Answer:

Question 16.

Use the open number line to find 40 + 23. Show your work.

Answer:

Question 17.

Find 43 + 8. Do the models correctly show the sum? Explain how you know.

Answer:

Solve each problem. Can you make a 10? Use place-value blocks if needed.

Answer:

**Pet Survey**

Maria asked other students what kind of pet they have. She made this chart.

Question 1.

How many Fish and Cats in all? Use the open number line to solve.

___ fish and cats

Answer:

Question 2.

How many Dogs and Birds in all? Use the hundred chart to add.

__ + __ = ___

__ dogs and birds

Answer:

Question 3.

Maria asks 18 students about their pets on Monday. She asks 17 students about their pets on Tuesday. How many students did she ask on both days?

Use place-value blocks to solve. Draw the blocks you used.

Did you need to make a 10 when you added the ones? Explain your answer.

Answer:

Question 4.

Maria adds other pets to her chart. 19 students in first grade have a rabbit. 24 students in second grade have a rabbit. How many students in all have rabbits?

**Part A**

Draw blocks to help you solve the problem.

**Part B**

Write an equation that matches the story.

Answer: