Tens and Ones: Understanding Place Value | 1st Grade Math

Grade 1 Math  ›  Numbers & Place Value  ›  Lesson 2

Grade 1 • Numbers & Place Value

Tens and Ones: Understanding Place Value

Discover how a group of 10 ones becomes 1 ten, use base-ten models and place value charts, and learn how the two digits in a two-digit number tell how many tens and ones there are.

✓ Colorful base-ten models ✓ 25 worked examples ✓ Hidden solutions ✓ 30 practice problems ✓ 15-question test

🎯 What You Will Learn

Make a ten
Understand that 10 ones can be bundled together and thought of as 1 ten.

Read tens and ones
Tell how many tens and how many ones are in a two-digit number.

Build two-digit numbers
Use tens rods, ones cubes, and a place value chart to make numbers.

Connect different forms
Connect a numeral such as 43 with 4 tens and 3 ones and with 40 + 3.

For parents & teachers — standards alignment: CCSS 1.NBT.B.2, especially 1.NBT.B.2a and 1.NBT.B.2c. Students understand that the two digits of a two-digit number represent amounts of tens and ones, that 10 ones can be thought of as 1 ten, and that whole tens such as 20, 30, and 40 are groups of tens with 0 ones. The teen-number case in 1.NBT.B.2b is developed separately in Lesson 3.

🧠 Key Vocabulary

one — one single object or unit.

ten — a group or bundle of 10 ones.

ones place — the place on the right in a two-digit number.

tens place — the place on the left in a two-digit number.

place value — the value a digit has because of where it is in a number.

expanded form — a way to show a number as the value of its tens and ones, such as 43 = 40 + 3.

🔟 Ten Ones Make One Ten

Our number system is built in groups of ten. When you have 10 ones, you can bundle them together and think of the bundle as 1 ten. The amount has not changed. It is still ten objects; we are simply organizing them in a helpful way.

1111111111

10 ones  =  1 ten

Think of pencils in a bundle: 10 single pencils can be tied together as one bundle of ten. The bundle still contains 10 pencils.

🧱 Tens Rods and Ones Cubes

In base-ten models, a long rod represents 1 ten. A small cube represents 1 one. We can use these models to see exactly how a two-digit number is built.

1 ten

One rod stands for 10 ones.

4 ones

Each small cube stands for 1 one.

🏠 The Tens Place and the Ones Place

A two-digit number has two places. The digit on the left tells how many tens there are. The digit on the right tells how many ones there are.

Tens

Ones

3

4

3 tens + 4 ones  =  30 + 4  =  34

Digit vs. value: In 64, the digit 6 is in the tens place, so it represents 6 tens and has a value of 60. The digit 4 is in the ones place, so it represents 4 ones and has a value of 4.

Watch the places: In 34, the 3 does not mean 3 ones. It means 3 tens. The 4 means 4 ones.

⭕ What Happens When There Are Zero Ones?

Numbers such as 20, 30, 40, and 90 have 0 ones. For example, 50 is 5 tens and 0 ones.

5 tens + 0 ones  =  50

Next lesson: Teen numbers such as 13, 16, and 19 are a special place-value pattern: each has 1 ten and some extra ones. We will explore them carefully in Lesson 3.

🌟 25 Worked Examples

✏️ Try each problem yourself first. Then tap “Show solution” to check your thinking.

1Make one ten

How many ones are bundled together to make 1 ten?

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A ten is a group of 10 ones. Answer: 10 ones make 1 ten.

2Read a base-ten model

The model shows 2 tens and 4 ones. What number is it?

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Two tens are 20. Four more ones make 24. Answer: 24.

3Break apart 53

How many tens and ones are in 53?

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The digit 5 is in the tens place, so there are 5 tens. The digit 3 is in the ones place, so there are 3 ones. Answer: 5 tens and 3 ones.

4A number with zero ones

How many tens and ones are in 70?

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70 is made of 7 tens and no extra ones. Answer: 7 tens and 0 ones.

5Build 41

Write the number that has 4 tens and 1 one.

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Four tens are 40. One more one makes 41. Answer: 41.

6Use a place value chart

The place value chart has 6 in the tens column and 2 in the ones column. What number does it show?

Tens

Ones

6

2

✨ Show solution 🙈 Hide solution

6 tens are 60 and 2 ones are 2. Together they make 62. Answer: 62.

7Count the rods and cubes

What number is shown by 3 tens and 7 ones?

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Three tens are 30. Seven ones are 7. 30 and 7 make 37. Answer: 37.

8Compose a number

What number is 8 tens and 2 ones?

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Eight tens are 80. Add 2 ones: 80 + 2 = 82. Answer: 82.

9Find the tens digit

In the number 47, which digit tells how many tens there are?

Tens

Ones

4

7

✨ Show solution 🙈 Hide solution

The left digit in a two-digit number is the tens digit. In 47, that digit is 4. Answer: 4.

10Find the ones digit

In the number 47, which digit tells how many ones there are?

Tens

Ones

4

7

✨ Show solution 🙈 Hide solution

The right digit in a two-digit number is the ones digit. In 47, that digit is 7. Answer: 7.

11What does the 6 mean?

In 64, the digit 6 is in the tens place. How many tens does it represent?

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The digit 6 is in the tens place, so it represents 6 tens. Six tens equal 60. Answer: 6 tens, or 60.

12What does the 4 mean?

In 64, the digit 4 is in the ones place. How many ones does it represent?

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The digit 4 is in the ones place, so it represents 4 ones. Answer: 4 ones.

13Write as tens and ones

Complete: 35 = □ tens and □ ones.

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The tens digit is 3 and the ones digit is 5. Answer: 35 = 3 tens and 5 ones.

14Write the number

Complete: 5 tens and 9 ones = □.

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Five tens are 50. Nine ones are 9. 50 + 9 = 59. Answer: 59.

15Whole tens

What number is 9 tens and 0 ones?

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Nine tens are 90. There are no extra ones. Answer: 90.

16Expanded form

Break 73 into tens and ones: 73 = □ + □.

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73 has 7 tens and 3 ones. Seven tens are 70, and three ones are 3. Answer: 73 = 70 + 3.

17Build from expanded form

What number is 40 + 6?

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40 is 4 tens and 6 is 6 ones. Together they make 46. Answer: 46.

18Match a model to a numeral

A model has 5 tens rods and 2 ones cubes. Which numeral matches the model?

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Five tens are 50 and two ones are 2. 50 + 2 = 52. Answer: 52.

19Check the statement

Is this statement true? 28 has 2 tens and 8 ones.

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Yes. In 28, the 2 is in the tens place and the 8 is in the ones place. Answer: Yes.

20Spot the mistake

Noah says 45 is 4 ones and 5 tens. What should he say instead?

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Noah switched the places. In 45, 4 is the tens digit and 5 is the ones digit. Answer: 45 is 4 tens and 5 ones.

21Another place value chart

What number does this chart show?

Tens

Ones

7

6

✨ Show solution 🙈 Hide solution

The chart shows 7 tens and 6 ones. Seven tens are 70, and 70 + 6 = 76. Answer: 76.

22Zero in the ones place

The number 30 has how many tens and how many ones?

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The 3 is in the tens place and the 0 is in the ones place. Answer: 3 tens and 0 ones.

23Represent 68

Write 68 as tens and ones and then in expanded form.

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68 has 6 tens and 8 ones. Six tens are 60. Answer: 6 tens and 8 ones; 68 = 60 + 8.

24Same digits, different places

Look at 27 and 72. In which number does the digit 7 represent 7 tens?

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In 27, the 7 is in the ones place. In 72, the 7 is in the tens place. Answer: 72.

25Challenge: connect three forms

A number has 6 tens and 7 ones. Write its numeral and expanded form.

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Six tens are 60 and seven ones are 7. Together they make 67. Answer: numeral 67; expanded form 60 + 7.

🎮 Independent Practice — 30 Problems

1. Complete: 24 = □ tens and □ ones.
2. Complete: 51 = □ tens and □ ones.
3. Complete: 86 = □ tens and □ ones.
4. Complete: 40 = □ tens and □ ones.
5. Complete: 90 = □ tens and □ ones.
6. Write the number: 3 tens and 6 ones = □.
7. Write the number: 7 tens and 1 one = □.
8. Write the number: 5 tens and 0 ones = □.
9. Write the number: 8 tens and 4 ones = □.
10. Write the number: 2 tens and 9 ones = □.
11. In 63, which digit is in the tens place?
12. In 63, which digit is in the ones place?
13. In 48, how many tens are there?
14. In 48, how many ones are there?
15. In 75, what does the digit 7 represent: 7 tens or 7 ones?
16. In 75, what does the digit 5 represent: 5 tens or 5 ones?
17. Complete: 32 = □ + □.
18. Complete: 57 = □ + □.
19. Complete: 91 = □ + □.
20. What number is 20 + 4?
21. What number is 60 + 9?
22. What number is 30 + 7?
23. A base-ten model has 4 tens rods and 3 ones cubes. What number does it show?
24. A base-ten model has 7 tens rods and no ones cubes. What number does it show?
25. A place value chart shows 5 tens and 8 ones. What number does it show?
26. True or false: 26 has 2 tens and 6 ones.
27. True or false: 81 has 8 ones and 1 ten.
28. Fix the mistake: “54 is 5 ones and 4 tens.”
29. Which number has 6 tens and 2 ones: 26, 62, or 60?
30. Challenge: Write 94 in three ways: as a numeral, as tens and ones, and in expanded form.

🏆 Lesson Test — 15 Questions

1. Complete: 42 = □ tens and □ ones.
2. Write the number: 6 tens and 5 ones = □.
3. In 73, which digit is in the tens place?
4. In 73, which digit is in the ones place?
5. Complete: 58 = □ + □.
6. What number is 80 + 3?
7. A model has 4 tens rods and 7 ones cubes. What number does it show?
8. True or false: 60 has 6 tens and 0 ones.
9. Maya says 29 is 2 ones and 9 tens. Correct her statement.
10. Challenge: Write 76 as tens and ones and in expanded form.
11. What number has 3 tens and 8 ones?
12. In 92, what value does the digit 9 represent?
13. Complete: 34 = 3 tens and □ ones.
14. A place value chart shows 2 tens and 5 ones. What number does it show?
15. Look at 27 and 72. In which number does the digit 2 represent 2 tens?

🔐 Complete Answer Key

🔑 Show practice answer key 🙈 Hide practice answer key

Practice Answers

1. 2 tens, 4 ones

2. 5 tens, 1 one

3. 8 tens, 6 ones

4. 4 tens, 0 ones

5. 9 tens, 0 ones

6. 36

7. 71

8. 50

9. 84

10. 29

11. 6

12. 3

13. 4 tens

14. 8 ones

15. 7 tens

16. 5 ones

17. 30 + 2

18. 50 + 7

19. 90 + 1

20. 24

21. 69

22. 37

23. 43

24. 70

25. 58

26. True

27. False — 81 has 8 tens and 1 one.

28. 54 is 5 tens and 4 ones.

29. 62

30. 94; 9 tens and 4 ones; 90 + 4

🏅 Show test answer key 🙈 Hide test answer key

Test Answers

1. 4 tens, 2 ones

2. 65

3. 7

4. 3

5. 50 + 8

6. 83

7. 47

8. True

9. 29 is 2 tens and 9 ones.

10. 7 tens and 6 ones; 70 + 6

11. 38

12. 90

13. 4

14. 25

15. 27

💡 Common Mistakes to Watch For

Switching the places
In 52, the 5 is tens and the 2 is ones—not the other way around.

Forgetting zero ones
70 means 7 tens and 0 ones.

Counting a ten rod as one
A tens rod stands for 10 ones, not 1 one.

Reading 4 tens as 4
Four tens have a value of 40.

For parents & teachers — Texas extension: Texas Grade 1 TEKS 1.2(B) asks students to compose and decompose numbers up to 120 with concrete and pictorial models, while 1.2(C) includes representing numbers up to 120 with objects, pictures, standard form, and expanded form. This lesson builds the tens-and-ones foundation before later work with numbers at and above 100.

🖨️ Printable Companion

A free Tens and Ones Place Value Practice Pack will be connected here as the MathLattice printable library grows. It will include base-ten models, place value charts, composing and decomposing two-digit numbers, expanded form, and an answer key.

← Lesson 1: Numbers to 120 Grade 1 Math Hub Next: Teen Numbers — One Ten and Some Ones →