Add the decimals and give the exact result: 0.63 + 0.37 = ? (Using Recovery-First Policy, these are ordinary terminating decimals, not repeating.)
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A1
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B1.01
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C0.99
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D1.10
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E0.9
Answer
Correct Answer: 1
Explanation
Introduction / Context:This question assesses accurate addition of terminating decimals. The original prompt formatting could be misread as repeating decimals (overlines), but under the Recovery-First Policy we interpret them as ordinary terminating decimals 0.63 and 0.37, which produce a clean integer sum common in decimal-fraction practice sets.
Given Data / Assumptions:
- Add 0.63 and 0.37 as standard terminating decimals.
- Align decimal places and add hundredths to hundredths, tenths to tenths.
Concept / Approach:Writing the numbers with the same number of decimal places (two) and adding columnwise ensures that place values are handled correctly. Carrying from hundredths to tenths is straightforward.
Step-by-Step Solution:0.63 + 0.37 = (0.60 + 0.03) + (0.30 + 0.07).Group tenths and hundredths: (0.60 + 0.30) + (0.03 + 0.07) = 0.90 + 0.10.Sum: 1.00.
Verification / Alternative check:As fractions: 0.63 = 63/100; 0.37 = 37/100; sum = 100/100 = 1.
Why Other Options Are Wrong:
- 1.01 and 1.10: Result from carrying errors or misaligned decimal places.
- 0.99: Comes from subtracting 0.37 from 0.63 or omitting carry.
- 0.9: Ignores the hundredths sum reaching 0.10.
Common Pitfalls:Misreading the problem as recurring decimals (which would yield 1.010101…); failing to align decimals; dropping the carry from 0.03 + 0.07.
Final Answer:1