Accurate decimal addition Compute the exact sum: 51.3 + 7.078 + 1.38 + 0.9.

Introduction / Context:Decimal arithmetic questions check precision with place values. Careful alignment and stepwise addition prevent typical carry/borrow errors and rounding slips.

Given Data / Assumptions:

• Add 51.3, 7.078, 1.38, and 0.9 exactly.
• All values are positive decimals.

Concept / Approach:Align decimal places and add systematically, or add in small groups to keep carries under control. No rounding is necessary because the addends have finite decimal expansions.

Step-by-Step Solution:First pair: 51.3 + 7.078 = 58.378.Add the next: 58.378 + 1.38 = 59.758.Add the last: 59.758 + 0.9 = 60.658.

Verification / Alternative check:Compute with full decimal alignment: 51.300 + 7.078 + 1.380 + 0.900 = 60.658. A calculator check confirms the total.

Why Other Options Are Wrong:61.668 and 59.238 are off by mis-placed carries; “None of these” is incorrect because an exact listed option exists; 60.586 reverses digits.

Common Pitfalls:Not aligning decimals; treating 0.9 as 0.09; rounding prematurely.

Final Answer:60.658