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Chapter 18: Adding Two-Digit Numbers Without 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 Without Regrouping with simple explanations, visual thinking, worked examples, practice, and review.

18.1 Adding tens

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 58 + 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: 81

Worked Example 2

Problem: Find 44 + 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: 67

Worked Example 3

Problem: Find 28 + 63.

  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: 91

Worked Example 4

Problem: Find 6 + 27.

  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 5

Problem: Find 6 + 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: 48

Worked Example 6

Problem: Find 20 + 18.

  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 7

Problem: Find 2 + 34.

  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 8

Problem: Find 8 + 12.

  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: 20

Worked Example 9

Problem: Find 4 + 36.

  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: 40

Worked Example 10

Problem: Find 70 + 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: 135

18.2 Adding ones

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 56 + 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: 79

Worked Example 2

Problem: Find 52 + 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: 109

Worked Example 3

Problem: Find 67 + 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: 134

Worked Example 4

Problem: Find 35 + 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: 54

Worked Example 5

Problem: Find 61 + 68.

  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: 129

Worked Example 6

Problem: Find 13 + 9.

  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: 22

Worked Example 7

Problem: Find 69 + 63.

  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: 132

Worked Example 8

Problem: Find 45 + 55.

  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: 100

Worked Example 9

Problem: Find 9 + 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: 38

Worked Example 10

Problem: Find 67 + 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: 112

18.3 Adding tens and ones

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 42 + 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: 87

Worked Example 2

Problem: Find 62 + 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: 131

Worked Example 3

Problem: Find 50 + 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: 111

Worked Example 4

Problem: Find 25 + 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: 50

Worked Example 5

Problem: Find 33 + 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: 38

Worked Example 6

Problem: Find 11 + 33.

  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: 44

Worked Example 7

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 8

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 9

Problem: Find 32 + 7.

  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: 39

Worked Example 10

Problem: Find 14 + 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: 59

18.4 Place-value drawings

Place-value drawings 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 19 and 13 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 2

Problem: Use 15 and 19 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 3

Problem: Use 11 and 6 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 4

Problem: Use 15 and 11 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 5

Problem: Use 15 and 11 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 6

Problem: Use 5 and 13 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 7

Problem: Use 11 and 2 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 8

Problem: Use 2 and 17 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 9

Problem: Use 1 and 15 to make a simple example about Place-value drawings.

  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 drawings.

Worked Example 10

Problem: Use 16 and 5 to make a simple example about Place-value drawings.

  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 drawings.

18.5 Open number-line 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 53 + 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: 55

Worked Example 2

Problem: Find 25 + 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: 54

Worked Example 3

Problem: Find 47 + 53.

  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: 100

Worked Example 4

Problem: Find 56 + 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: 94

Worked Example 5

Problem: Find 37 + 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: 97

Worked Example 6

Problem: Find 49 + 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: 94

Worked Example 7

Problem: Find 49 + 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: 89

Worked Example 8

Problem: Find 17 + 30.

  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: 47

Worked Example 9

Problem: Find 61 + 28.

  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: 89

Worked Example 10

Problem: Find 39 + 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: 81

18.6 Breaking apart addends

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 56 + 55.

  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: 111

Worked Example 2

Problem: Find 31 + 63.

  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 3

Problem: Find 7 + 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: 66

Worked Example 4

Problem: Find 45 + 35.

  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: 80

Worked Example 5

Problem: Find 5 + 36.

  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 6

Problem: Find 68 + 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: 125

Worked Example 7

Problem: Find 66 + 3.

  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 8

Problem: Find 47 + 4.

  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: 51

Worked Example 9

Problem: Find 57 + 4.

  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: 61

Worked Example 10

Problem: Find 34 + 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: 49

18.7 Partial sums

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 9 + 43.

  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 16 + 49.

  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 3

Problem: Find 46 + 4.

  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: 50

Worked Example 4

Problem: Find 53 + 55.

  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: 108

Worked Example 5

Problem: Find 35 + 56.

  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: 91

Worked Example 6

Problem: Find 69 + 51.

  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: 120

Worked Example 7

Problem: Find 58 + 51.

  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 8

Problem: Find 20 + 48.

  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: 68

Worked Example 9

Problem: Find 42 + 56.

  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: 98

Worked Example 10

Problem: Find 33 + 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: 100

18.8 Vertical 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 56 + 27.

  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 2

Problem: Find 28 + 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: 70

Worked Example 3

Problem: Find 57 + 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: 62

Worked Example 4

Problem: Find 26 + 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: 51

Worked Example 5

Problem: Find 59 + 51.

  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: 110

Worked Example 6

Problem: Find 67 + 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: 132

Worked Example 7

Problem: Find 53 + 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: 120

Worked Example 8

Problem: Find 33 + 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: 57

Worked Example 9

Problem: Find 26 + 50.

  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: 76

Worked Example 10

Problem: Find 70 + 52.

  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: 122

18.9 Estimating before adding

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 9 + 70.

  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 2

Problem: Find 30 + 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: 84

Worked Example 3

Problem: Find 53 + 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: 66

Worked Example 4

Problem: Find 61 + 53.

  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: 114

Worked Example 5

Problem: Find 45 + 36.

  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 6

Problem: Find 28 + 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: 82

Worked Example 7

Problem: Find 24 + 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: 91

Worked Example 8

Problem: Find 24 + 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: 43

Worked Example 9

Problem: Find 52 + 12.

  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 10

Problem: Find 14 + 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: 59

18.10 Word problems

Word problems 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 14 and 6 to make a simple example about Word problems.

  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.

Worked Example 2

Problem: Use 3 and 4 to make a simple example about Word problems.

  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.

Worked Example 3

Problem: Use 14 and 8 to make a simple example about Word problems.

  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.

Worked Example 4

Problem: Use 13 and 7 to make a simple example about Word problems.

  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.

Worked Example 5

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

  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.

Worked Example 6

Problem: Use 8 and 20 to make a simple example about Word problems.

  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.

Worked Example 7

Problem: Use 20 and 7 to make a simple example about Word problems.

  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.

Worked Example 8

Problem: Use 6 and 17 to make a simple example about Word problems.

  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.

Worked Example 9

Problem: Use 19 and 7 to make a simple example about Word problems.

  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.

Worked Example 10

Problem: Use 4 and 17 to make a simple example about Word problems.

  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.

18.11 Checking by another strategy

Checking by another strategy 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 12 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 2

Problem: Use 8 and 16 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 3

Problem: Use 9 and 10 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 4

Problem: Use 1 and 2 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 5

Problem: Use 19 and 9 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 6

Problem: Use 3 and 20 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 7

Problem: Use 19 and 9 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 8

Problem: Use 11 and 8 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 9

Problem: Use 10 and 2 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

Worked Example 10

Problem: Use 1 and 2 to make a simple example about Checking by another strategy.

  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 Checking by another strategy.

18.12 Choosing an efficient method

Choosing an efficient method 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 20 and 4 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 2

Problem: Use 4 and 19 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 3

Problem: Use 5 and 2 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 4

Problem: Use 4 and 9 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 5

Problem: Use 14 and 11 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 6

Problem: Use 5 and 16 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 7

Problem: Use 10 and 17 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 8

Problem: Use 19 and 19 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 9

Problem: Use 19 and 16 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

Worked Example 10

Problem: Use 17 and 8 to make a simple example about Choosing an efficient method.

  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 Choosing an efficient method.

30 Review Questions and Answers

Q1. What should a Grade 2 learner understand about Adding tens?

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

Q2. What should a Grade 2 learner understand about Adding ones?

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

Q3. What should a Grade 2 learner understand about Adding tens and ones?

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

Q4. What should a Grade 2 learner understand about Place-value drawings?

Answer: Place-value drawings 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 Open number-line addition?

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

Q6. What should a Grade 2 learner understand about Breaking apart addends?

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

Q7. What should a Grade 2 learner understand about Partial sums?

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

Q8. What should a Grade 2 learner understand about Vertical addition?

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

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

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?

Answer: Word problems 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 by another strategy?

Answer: Checking by another strategy is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q12. What should a Grade 2 learner understand about Choosing an efficient method?

Answer: Choosing an efficient method 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 Adding tens?

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

Q14. What should a Grade 2 learner understand about Adding ones?

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

Q15. What should a Grade 2 learner understand about Adding tens and ones?

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

Q16. What should a Grade 2 learner understand about Place-value drawings?

Answer: Place-value drawings 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 Open number-line addition?

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

Q18. What should a Grade 2 learner understand about Breaking apart addends?

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

Q19. What should a Grade 2 learner understand about Partial sums?

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

Q20. What should a Grade 2 learner understand about Vertical addition?

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

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

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?

Answer: Word problems 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 by another strategy?

Answer: Checking by another strategy is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q24. What should a Grade 2 learner understand about Choosing an efficient method?

Answer: Choosing an efficient method 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 Adding tens?

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

Q26. What should a Grade 2 learner understand about Adding ones?

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

Q27. What should a Grade 2 learner understand about Adding tens and ones?

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

Q28. What should a Grade 2 learner understand about Place-value drawings?

Answer: Place-value drawings 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 Open number-line addition?

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

Q30. What should a Grade 2 learner understand about Breaking apart addends?

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