Add the decimals and give the exact result: 0.63 + 0.37 = ? (Using Recovery-First Policy, these are ordinary terminating decimals, not repeating.)

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