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Chapter 19: Adding Two-Digit Numbers With Regrouping

Learn Grade 2 mathematics with very-beginner explanations, original worked examples, practice, reasoning, and review.

Grade 2Very Beginner Friendly10 Examples Per Topic30 Q&APractice + Review
Estimated reading time0% read
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Chapter Overview

This chapter teaches Adding Two-Digit Numbers With Regrouping with simple explanations, visual thinking, worked examples, practice, and review.

19.1 Making a new ten

Making a new ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Use 5 and 4 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 2

Problem: Use 13 and 10 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 3

Problem: Use 16 and 15 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 4

Problem: Use 20 and 9 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 5

Problem: Use 11 and 6 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 6

Problem: Use 6 and 14 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 7

Problem: Use 17 and 9 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 8

Problem: Use 4 and 16 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 9

Problem: Use 8 and 11 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

Worked Example 10

Problem: Use 15 and 2 to make a simple example about Making a new ten.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Making a new ten.

19.2 Regrouping ones as a ten

Place value tells how much a digit is worth because of its position in a number. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: How many hundreds, tens, and ones are in 175?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 7 tens, 5 ones

Worked Example 2

Problem: How many hundreds, tens, and ones are in 159?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 5 tens, 9 ones

Worked Example 3

Problem: How many hundreds, tens, and ones are in 107?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 0 tens, 7 ones

Worked Example 4

Problem: How many hundreds, tens, and ones are in 135?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 3 tens, 5 ones

Worked Example 5

Problem: How many hundreds, tens, and ones are in 102?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 0 tens, 2 ones

Worked Example 6

Problem: How many hundreds, tens, and ones are in 109?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 0 tens, 9 ones

Worked Example 7

Problem: How many hundreds, tens, and ones are in 193?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 9 tens, 3 ones

Worked Example 8

Problem: How many hundreds, tens, and ones are in 145?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 4 tens, 5 ones

Worked Example 9

Problem: How many hundreds, tens, and ones are in 192?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 9 tens, 2 ones

Worked Example 10

Problem: How many hundreds, tens, and ones are in 118?

  1. Read the hundreds digit.
  2. Read the tens digit.
  3. Read the ones digit.

Very beginner explanation: Position tells place value.

Answer: 1 hundred, 1 tens, 8 ones

19.3 Place-value models for regrouping

Place-value models for regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Use 13 and 6 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 2

Problem: Use 15 and 9 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 3

Problem: Use 3 and 4 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 4

Problem: Use 15 and 20 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 5

Problem: Use 8 and 11 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 6

Problem: Use 13 and 9 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 7

Problem: Use 9 and 7 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 8

Problem: Use 6 and 19 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 9

Problem: Use 15 and 7 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

Worked Example 10

Problem: Use 15 and 3 to make a simple example about Place-value models for regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Place-value models for regrouping.

19.4 Open number-line regrouping

Open number-line regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Use 9 and 12 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 2

Problem: Use 11 and 9 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 3

Problem: Use 14 and 7 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 4

Problem: Use 13 and 8 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 5

Problem: Use 6 and 13 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 6

Problem: Use 5 and 18 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 7

Problem: Use 12 and 3 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 8

Problem: Use 8 and 6 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 9

Problem: Use 19 and 17 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

Worked Example 10

Problem: Use 18 and 9 to make a simple example about Open number-line regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Open number-line regrouping.

19.5 Breaking apart numbers

Breaking apart numbers is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Use 15 and 20 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 2

Problem: Use 5 and 16 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 3

Problem: Use 15 and 11 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 4

Problem: Use 14 and 15 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 5

Problem: Use 4 and 8 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 6

Problem: Use 12 and 17 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 7

Problem: Use 2 and 16 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 8

Problem: Use 1 and 15 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 9

Problem: Use 20 and 13 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

Worked Example 10

Problem: Use 1 and 18 to make a simple example about Breaking apart numbers.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Breaking apart numbers.

19.6 Partial sums with regrouping

Addition combines quantities. Counting on, making ten, drawings, and place value can help. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Find 51 + 58.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 109

Worked Example 2

Problem: Find 28 + 10.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 38

Worked Example 3

Problem: Find 42 + 32.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 74

Worked Example 4

Problem: Find 36 + 45.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 81

Worked Example 5

Problem: Find 7 + 66.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 73

Worked Example 6

Problem: Find 43 + 13.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 56

Worked Example 7

Problem: Find 58 + 61.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 119

Worked Example 8

Problem: Find 19 + 62.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 81

Worked Example 9

Problem: Find 21 + 69.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 90

Worked Example 10

Problem: Find 63 + 2.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 65

19.7 Vertical addition with regrouping

Addition combines quantities. Counting on, making ten, drawings, and place value can help. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Find 21 + 25.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 46

Worked Example 2

Problem: Find 18 + 40.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 58

Worked Example 3

Problem: Find 57 + 58.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 115

Worked Example 4

Problem: Find 37 + 42.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 79

Worked Example 5

Problem: Find 7 + 64.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 71

Worked Example 6

Problem: Find 2 + 39.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 41

Worked Example 7

Problem: Find 36 + 54.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 90

Worked Example 8

Problem: Find 51 + 44.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 95

Worked Example 9

Problem: Find 26 + 23.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 49

Worked Example 10

Problem: Find 46 + 2.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 48

19.8 Adding near a multiple of ten

Addition combines quantities. Counting on, making ten, drawings, and place value can help. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Find 49 + 17.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 66

Worked Example 2

Problem: Find 22 + 14.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 36

Worked Example 3

Problem: Find 65 + 38.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 103

Worked Example 4

Problem: Find 44 + 29.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 73

Worked Example 5

Problem: Find 35 + 69.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 104

Worked Example 6

Problem: Find 24 + 41.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 65

Worked Example 7

Problem: Find 41 + 5.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 46

Worked Example 8

Problem: Find 22 + 66.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 88

Worked Example 9

Problem: Find 11 + 5.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 16

Worked Example 10

Problem: Find 39 + 57.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 96

19.9 Estimating a sum

Addition combines quantities. Counting on, making ten, drawings, and place value can help. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Find 26 + 26.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 52

Worked Example 2

Problem: Find 55 + 60.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 115

Worked Example 3

Problem: Find 60 + 61.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 121

Worked Example 4

Problem: Find 45 + 24.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 69

Worked Example 5

Problem: Find 35 + 59.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 94

Worked Example 6

Problem: Find 52 + 29.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 81

Worked Example 7

Problem: Find 16 + 19.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 35

Worked Example 8

Problem: Find 12 + 15.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 27

Worked Example 9

Problem: Find 17 + 42.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 59

Worked Example 10

Problem: Find 48 + 21.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 69

19.10 Word problems with regrouping

Word problems with regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Use 6 and 10 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 2

Problem: Use 9 and 15 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 3

Problem: Use 11 and 12 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 4

Problem: Use 15 and 12 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 5

Problem: Use 11 and 11 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 6

Problem: Use 8 and 3 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 7

Problem: Use 3 and 19 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 8

Problem: Use 9 and 5 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 9

Problem: Use 7 and 11 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

Worked Example 10

Problem: Use 15 and 7 to make a simple example about Word problems with regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Word problems with regrouping.

19.11 Checking addition

Addition combines quantities. Counting on, making ten, drawings, and place value can help. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Find 18 + 10.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 28

Worked Example 2

Problem: Find 19 + 15.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 34

Worked Example 3

Problem: Find 10 + 67.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 77

Worked Example 4

Problem: Find 68 + 15.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 83

Worked Example 5

Problem: Find 17 + 45.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 62

Worked Example 6

Problem: Find 48 + 16.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 64

Worked Example 7

Problem: Find 32 + 26.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 58

Worked Example 8

Problem: Find 61 + 67.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 128

Worked Example 9

Problem: Find 4 + 29.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 33

Worked Example 10

Problem: Find 23 + 65.

  1. Start with the larger number.
  2. Add tens or make a ten if helpful.
  3. Add the remaining ones.

Very beginner explanation: Addition combines quantities.

Answer: 88

19.12 Explaining regrouping

Explaining regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Use 10 and 15 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 2

Problem: Use 16 and 14 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 3

Problem: Use 14 and 8 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 4

Problem: Use 14 and 4 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 5

Problem: Use 11 and 13 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 6

Problem: Use 9 and 13 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 7

Problem: Use 12 and 4 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 8

Problem: Use 5 and 19 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 9

Problem: Use 15 and 2 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

Worked Example 10

Problem: Use 6 and 3 to make a simple example about Explaining regrouping.

  1. Recall the topic meaning.
  2. Use objects, a drawing, or a number sentence.
  3. Check that the example matches the idea.

Very beginner explanation: Simple models make Grade 2 ideas easier to understand.

Answer: A correct Grade 2 example of Explaining regrouping.

30 Review Questions and Answers

Q1. What should a Grade 2 learner understand about Making a new ten?

Answer: Making a new ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q2. What should a Grade 2 learner understand about Regrouping ones as a ten?

Answer: Place value tells how much a digit is worth because of its position in a number.

Q3. What should a Grade 2 learner understand about Place-value models for regrouping?

Answer: Place-value models for regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q4. What should a Grade 2 learner understand about Open number-line regrouping?

Answer: Open number-line regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q5. What should a Grade 2 learner understand about Breaking apart numbers?

Answer: Breaking apart numbers is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q6. What should a Grade 2 learner understand about Partial sums with regrouping?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q7. What should a Grade 2 learner understand about Vertical addition with regrouping?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q8. What should a Grade 2 learner understand about Adding near a multiple of ten?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q9. What should a Grade 2 learner understand about Estimating a sum?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q10. What should a Grade 2 learner understand about Word problems with regrouping?

Answer: Word problems with regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q11. What should a Grade 2 learner understand about Checking addition?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q12. What should a Grade 2 learner understand about Explaining regrouping?

Answer: Explaining regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q13. What should a Grade 2 learner understand about Making a new ten?

Answer: Making a new ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q14. What should a Grade 2 learner understand about Regrouping ones as a ten?

Answer: Place value tells how much a digit is worth because of its position in a number.

Q15. What should a Grade 2 learner understand about Place-value models for regrouping?

Answer: Place-value models for regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q16. What should a Grade 2 learner understand about Open number-line regrouping?

Answer: Open number-line regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q17. What should a Grade 2 learner understand about Breaking apart numbers?

Answer: Breaking apart numbers is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q18. What should a Grade 2 learner understand about Partial sums with regrouping?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q19. What should a Grade 2 learner understand about Vertical addition with regrouping?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q20. What should a Grade 2 learner understand about Adding near a multiple of ten?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q21. What should a Grade 2 learner understand about Estimating a sum?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q22. What should a Grade 2 learner understand about Word problems with regrouping?

Answer: Word problems with regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q23. What should a Grade 2 learner understand about Checking addition?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.

Q24. What should a Grade 2 learner understand about Explaining regrouping?

Answer: Explaining regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q25. What should a Grade 2 learner understand about Making a new ten?

Answer: Making a new ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q26. What should a Grade 2 learner understand about Regrouping ones as a ten?

Answer: Place value tells how much a digit is worth because of its position in a number.

Q27. What should a Grade 2 learner understand about Place-value models for regrouping?

Answer: Place-value models for regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q28. What should a Grade 2 learner understand about Open number-line regrouping?

Answer: Open number-line regrouping is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q29. What should a Grade 2 learner understand about Breaking apart numbers?

Answer: Breaking apart numbers is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q30. What should a Grade 2 learner understand about Partial sums with regrouping?

Answer: Addition combines quantities. Counting on, making ten, drawings, and place value can help.