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Chapter 10: Nearest Ten and Estimation

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 Nearest Ten and Estimation with simple explanations, visual thinking, worked examples, practice, and review.

10.1 Finding the two nearest tens

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 176?

  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, 6 ones

Worked Example 2

Problem: How many hundreds, tens, and ones are in 141?

  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, 1 ones

Worked Example 3

Problem: How many hundreds, tens, and ones are in 156?

  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, 6 ones

Worked Example 4

Problem: How many hundreds, tens, and ones are in 132?

  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, 2 ones

Worked Example 5

Problem: How many hundreds, tens, and ones are in 153?

  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, 3 ones

Worked Example 6

Problem: How many hundreds, tens, and ones are in 110?

  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, 0 ones

Worked Example 7

Problem: How many hundreds, tens, and ones are in 166?

  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, 6 tens, 6 ones

Worked Example 8

Problem: How many hundreds, tens, and ones are in 161?

  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, 6 tens, 1 ones

Worked Example 9

Problem: How many hundreds, tens, and ones are in 151?

  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, 1 ones

Worked Example 10

Problem: How many hundreds, tens, and ones are in 101?

  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, 1 ones

10.2 Numbers closer to the lower ten

Numbers closer to the lower 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 11 and 13 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 2

Problem: Use 13 and 13 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 3

Problem: Use 20 and 5 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 4

Problem: Use 1 and 20 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 5

Problem: Use 14 and 5 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 6

Problem: Use 14 and 19 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 7

Problem: Use 8 and 6 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 8

Problem: Use 6 and 4 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 9

Problem: Use 11 and 19 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

Worked Example 10

Problem: Use 6 and 9 to make a simple example about Numbers closer to the lower 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 Numbers closer to the lower ten.

10.3 Numbers closer to the higher ten

Numbers closer to the higher 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 2 and 3 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 2

Problem: Use 14 and 16 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 3

Problem: Use 1 and 14 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 4

Problem: Use 20 and 12 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 5

Problem: Use 5 and 6 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 6

Problem: Use 15 and 8 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 7

Problem: Use 10 and 4 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 8

Problem: Use 20 and 9 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 9

Problem: Use 5 and 10 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

Worked Example 10

Problem: Use 20 and 7 to make a simple example about Numbers closer to the higher 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 Numbers closer to the higher ten.

10.4 Midpoints between tens

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 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 2

Problem: How many hundreds, tens, and ones are in 137?

  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, 7 ones

Worked Example 3

Problem: How many hundreds, tens, and ones are in 138?

  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, 8 ones

Worked Example 4

Problem: How many hundreds, tens, and ones are in 108?

  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, 8 ones

Worked Example 5

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 6

Problem: How many hundreds, tens, and ones are in 164?

  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, 6 tens, 4 ones

Worked Example 7

Problem: How many hundreds, tens, and ones are in 194?

  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, 4 ones

Worked Example 8

Problem: How many hundreds, tens, and ones are in 137?

  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, 7 ones

Worked Example 9

Problem: How many hundreds, tens, and ones are in 144?

  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, 4 ones

Worked Example 10

Problem: How many hundreds, tens, and ones are in 104?

  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, 4 ones

10.5 Using ten frames to estimate

Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Which ten is closer to 78: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 2

Problem: Which ten is closer to 61: 60 or 70?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 60

Worked Example 3

Problem: Which ten is closer to 33: 30 or 40?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 30

Worked Example 4

Problem: Which ten is closer to 11: 10 or 20?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 10

Worked Example 5

Problem: Which ten is closer to 27: 20 or 30?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 30

Worked Example 6

Problem: Which ten is closer to 36: 30 or 40?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 40

Worked Example 7

Problem: Which ten is closer to 76: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 8

Problem: Which ten is closer to 76: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 9

Problem: Which ten is closer to 78: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 10

Problem: Which ten is closer to 23: 20 or 30?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 20

10.6 Using number lines to find the nearest ten

Counting patterns organize numbers and help with addition, subtraction, and number relationships. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Continue 14, 19, 24, ...

  1. The rule is add 5.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 29, 34

Worked Example 2

Problem: Continue 34, 44, 54, ...

  1. The rule is add 10.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 64, 74

Worked Example 3

Problem: Continue 1, 6, 11, ...

  1. The rule is add 5.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 16, 21

Worked Example 4

Problem: Continue 17, 22, 27, ...

  1. The rule is add 5.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 32, 37

Worked Example 5

Problem: Continue 9, 10, 11, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 12, 13

Worked Example 6

Problem: Continue 2, 3, 4, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 5, 6

Worked Example 7

Problem: Continue 3, 13, 23, ...

  1. The rule is add 10.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 33, 43

Worked Example 8

Problem: Continue 21, 22, 23, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 24, 25

Worked Example 9

Problem: Continue 32, 33, 34, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 35, 36

Worked Example 10

Problem: Continue 24, 34, 44, ...

  1. The rule is add 10.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 54, 64

10.7 Estimating a collection

Estimating a collection 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 5 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 2

Problem: Use 10 and 19 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 3

Problem: Use 12 and 8 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 4

Problem: Use 20 and 1 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 5

Problem: Use 11 and 10 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 6

Problem: Use 16 and 4 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 7

Problem: Use 9 and 7 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 8

Problem: Use 14 and 14 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 9

Problem: Use 7 and 10 to make a simple example about Estimating a collection.

  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 Estimating a collection.

Worked Example 10

Problem: Use 6 and 18 to make a simple example about Estimating a collection.

  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 Estimating a collection.

10.8 Checking an estimate by counting

Counting patterns organize numbers and help with addition, subtraction, and number relationships. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Continue 21, 23, 25, ...

  1. The rule is add 2.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 27, 29

Worked Example 2

Problem: Continue 30, 31, 32, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 33, 34

Worked Example 3

Problem: Continue 26, 36, 46, ...

  1. The rule is add 10.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 56, 66

Worked Example 4

Problem: Continue 28, 38, 48, ...

  1. The rule is add 10.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 58, 68

Worked Example 5

Problem: Continue 32, 33, 34, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 35, 36

Worked Example 6

Problem: Continue 38, 40, 42, ...

  1. The rule is add 2.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 44, 46

Worked Example 7

Problem: Continue 31, 41, 51, ...

  1. The rule is add 10.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 61, 71

Worked Example 8

Problem: Continue 32, 33, 34, ...

  1. The rule is add 1.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 35, 36

Worked Example 9

Problem: Continue 17, 19, 21, ...

  1. The rule is add 2.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 23, 25

Worked Example 10

Problem: Continue 18, 23, 28, ...

  1. The rule is add 5.
  2. Use the same rule again.

Very beginner explanation: Counting patterns use a consistent step.

Answer: 33, 38

10.9 Reasonable versus unreasonable estimates

Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Which ten is closer to 65: 60 or 70?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 70

Worked Example 2

Problem: Which ten is closer to 84: 80 or 90?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 3

Problem: Which ten is closer to 64: 60 or 70?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 60

Worked Example 4

Problem: Which ten is closer to 41: 40 or 50?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 40

Worked Example 5

Problem: Which ten is closer to 23: 20 or 30?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 20

Worked Example 6

Problem: Which ten is closer to 91: 90 or 100?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 90

Worked Example 7

Problem: Which ten is closer to 32: 30 or 40?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 30

Worked Example 8

Problem: Which ten is closer to 93: 90 or 100?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 90

Worked Example 9

Problem: Which ten is closer to 78: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 10

Problem: Which ten is closer to 46: 40 or 50?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 50

10.10 Estimating before 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 12 + 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: 66

Worked Example 2

Problem: Find 7 + 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: 62

Worked Example 3

Problem: Find 29 + 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: 32

Worked Example 4

Problem: Find 6 + 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: 68

Worked Example 5

Problem: Find 64 + 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: 97

Worked Example 6

Problem: Find 33 + 31.

  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 57 + 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: 72

Worked Example 8

Problem: Find 48 + 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: 114

Worked Example 9

Problem: Find 67 + 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: 107

Worked Example 10

Problem: Find 40 + 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: 63

10.11 Estimating before subtraction

Subtraction can mean taking away, finding a difference, or finding a missing part. Addition can check the answer. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Find 132 − 116.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 16

Worked Example 2

Problem: Find 64 − 41.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 23

Worked Example 3

Problem: Find 44 − 35.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 9

Worked Example 4

Problem: Find 99 − 49.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 50

Worked Example 5

Problem: Find 106 − 7.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 99

Worked Example 6

Problem: Find 74 − 14.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 60

Worked Example 7

Problem: Find 134 − 69.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 65

Worked Example 8

Problem: Find 85 − 46.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 39

Worked Example 9

Problem: Find 26 − 25.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 1

Worked Example 10

Problem: Find 147 − 139.

  1. Start with the larger number.
  2. Take away or count up.
  3. Check with addition.

Very beginner explanation: Subtraction finds what remains or the difference.

Answer: 8

10.12 Explaining why an estimate makes sense

Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number. Use objects, drawings, number lines, tables, or number sentences when useful.

10 Worked Examples with Answers

Worked Example 1

Problem: Which ten is closer to 58: 50 or 60?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 60

Worked Example 2

Problem: Which ten is closer to 71: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 70

Worked Example 3

Problem: Which ten is closer to 77: 70 or 80?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 80

Worked Example 4

Problem: Which ten is closer to 63: 60 or 70?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 60

Worked Example 5

Problem: Which ten is closer to 37: 30 or 40?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 40

Worked Example 6

Problem: Which ten is closer to 62: 60 or 70?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 60

Worked Example 7

Problem: Which ten is closer to 99: 90 or 100?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 100

Worked Example 8

Problem: Which ten is closer to 47: 40 or 50?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 50

Worked Example 9

Problem: Which ten is closer to 44: 40 or 50?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 40

Worked Example 10

Problem: Which ten is closer to 87: 80 or 90?

  1. Find the distance to each ten.
  2. Choose the closer one.

Very beginner explanation: Nearest-ten thinking uses multiples of ten as benchmarks.

Answer: 90

30 Review Questions and Answers

Q1. What should a Grade 2 learner understand about Finding the two nearest tens?

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

Q2. What should a Grade 2 learner understand about Numbers closer to the lower ten?

Answer: Numbers closer to the lower ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q3. What should a Grade 2 learner understand about Numbers closer to the higher ten?

Answer: Numbers closer to the higher ten 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 Midpoints between tens?

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

Q5. What should a Grade 2 learner understand about Using ten frames to estimate?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q6. What should a Grade 2 learner understand about Using number lines to find the nearest ten?

Answer: Counting patterns organize numbers and help with addition, subtraction, and number relationships.

Q7. What should a Grade 2 learner understand about Estimating a collection?

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

Q8. What should a Grade 2 learner understand about Checking an estimate by counting?

Answer: Counting patterns organize numbers and help with addition, subtraction, and number relationships.

Q9. What should a Grade 2 learner understand about Reasonable versus unreasonable estimates?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q10. What should a Grade 2 learner understand about Estimating before addition?

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

Q11. What should a Grade 2 learner understand about Estimating before subtraction?

Answer: Subtraction can mean taking away, finding a difference, or finding a missing part. Addition can check the answer.

Q12. What should a Grade 2 learner understand about Explaining why an estimate makes sense?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q13. What should a Grade 2 learner understand about Finding the two nearest tens?

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

Q14. What should a Grade 2 learner understand about Numbers closer to the lower ten?

Answer: Numbers closer to the lower ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q15. What should a Grade 2 learner understand about Numbers closer to the higher ten?

Answer: Numbers closer to the higher ten 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 Midpoints between tens?

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

Q17. What should a Grade 2 learner understand about Using ten frames to estimate?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q18. What should a Grade 2 learner understand about Using number lines to find the nearest ten?

Answer: Counting patterns organize numbers and help with addition, subtraction, and number relationships.

Q19. What should a Grade 2 learner understand about Estimating a collection?

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

Q20. What should a Grade 2 learner understand about Checking an estimate by counting?

Answer: Counting patterns organize numbers and help with addition, subtraction, and number relationships.

Q21. What should a Grade 2 learner understand about Reasonable versus unreasonable estimates?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q22. What should a Grade 2 learner understand about Estimating before addition?

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

Q23. What should a Grade 2 learner understand about Estimating before subtraction?

Answer: Subtraction can mean taking away, finding a difference, or finding a missing part. Addition can check the answer.

Q24. What should a Grade 2 learner understand about Explaining why an estimate makes sense?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q25. What should a Grade 2 learner understand about Finding the two nearest tens?

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

Q26. What should a Grade 2 learner understand about Numbers closer to the lower ten?

Answer: Numbers closer to the lower ten is a Grade 2 math idea best learned with simple numbers, objects, drawings, and clear words.

Q27. What should a Grade 2 learner understand about Numbers closer to the higher ten?

Answer: Numbers closer to the higher ten 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 Midpoints between tens?

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

Q29. What should a Grade 2 learner understand about Using ten frames to estimate?

Answer: Estimation gives a nearby amount. The nearest ten is the multiple of ten closest to the number.

Q30. What should a Grade 2 learner understand about Using number lines to find the nearest ten?

Answer: Counting patterns organize numbers and help with addition, subtraction, and number relationships.