To solve the problems, we need to estimate the results of each arithmetic operation by rounding off to the nearest ten. Let's go through each question step by step.
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1) What is the best estimate of 89 plus 13?
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Step 1: Round 89 to the nearest ten.
- 89 rounds to 90.
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Step 2: Round 13 to the nearest ten.
- 13 rounds to 10.
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Step 3: Add the rounded numbers.
- \( 90 + 10 = 100 \).
Answer: B. 100
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2) What is the best estimate of 65 minus 24?
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Step 1: Round 65 to the nearest ten.
- 65 rounds to 70.
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Step 2: Round 24 to the nearest ten.
- 24 rounds to 20.
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Step 3: Subtract the rounded numbers.
- \( 70 - 20 = 50 \).
Answer: C. 50
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3) What is the best estimate of 42 plus 76?
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Step 1: Round 42 to the nearest ten.
- 42 rounds to 40.
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Step 2: Round 76 to the nearest ten.
- 76 rounds to 80.
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Step 3: Add the rounded numbers.
- \( 40 + 80 = 120 \).
Answer: C. 120
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4) What is the best estimate of 18 plus 52?
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Step 1: Round 18 to the nearest ten.
- 18 rounds to 20.
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Step 2: Round 52 to the nearest ten.
- 52 rounds to 50.
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Step 3: Add the rounded numbers.
- \( 20 + 50 = 70 \).
Answer: A. 70
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5) What is the best estimate of 68 minus 44?
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Step 1: Round 68 to the nearest ten.
- 68 rounds to 70.
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Step 2: Round 44 to the nearest ten.
- 44 rounds to 40.
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Step 3: Subtract the rounded numbers.
- \( 70 - 40 = 30 \).
Answer: D. 30
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6) What is the best estimate of 91 minus 15?
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Step 1: Round 91 to the nearest ten.
- 91 rounds to 90.
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Step 2: Round 15 to the nearest ten.
- 15 rounds to 20.
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Step 3: Subtract the rounded numbers.
- \( 90 - 20 = 70 \).
Answer: B. 70
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7) What is the best estimate of 27 plus 24?
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Step 1: Round 27 to the nearest ten.
- 27 rounds to 30.
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Step 2: Round 24 to the nearest ten.
- 24 rounds to 20.
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Step 3: Add the rounded numbers.
- \( 30 + 20 = 50 \).
Answer: A. 50
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8) What is the best estimate of 82 plus 16?
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Step 1: Round 82 to the nearest ten.
- 82 rounds to 80.
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Step 2: Round 16 to the nearest ten.
- 16 rounds to 20.
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Step 3: Add the rounded numbers.
- \( 80 + 20 = 100 \).
Answer: D. 100
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Final Answers:
1. B. 100
2. C. 50
3. C. 120
4. A. 70
5. D. 30
6. B. 70
7. A. 50
8. D. 100
Boxed Answer:
\[
\boxed{B, C, C, A, D, B, A, D}
\]
Parent Tip: Review the logic above to help your child master the concept of multiple choice addition worksheet.
