Scientific notation check — evaluate the statement: “Subtracting 18 × 10^2 from 480 × 10^1 gives 30 × 10^2.” Is this arithmetic statement valid?
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ACorrect
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BIncorrect
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CValid only if units cancel
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DCannot be determined
Answer
Correct Answer: Correct
Explanation
Introduction / Context:Scientific notation is a compact way to handle large and small numbers in electronics, physics, and engineering calculations. This problem asks you to validate a subtraction expressed in scientific-notation style and to recognize appropriate normalization.
Given Data / Assumptions:
- Two quantities: 480 × 10^1 and 18 × 10^2.
- We are checking the raw arithmetic equivalence, not significant figures or unit conversions.
- No units are attached; treat both numbers as pure magnitudes.
Concept / Approach:The easiest way to verify is to convert both terms into ordinary integers and perform the subtraction, then re-express the result in scientific notation. Alternatively, align powers of ten and subtract the mantissas accordingly.
Step-by-Step Solution:
Compute each term: 480 × 10^1 = 4800; 18 × 10^2 = 1800.Subtract: 4800 − 1800 = 3000.Express the result: 3000 = 30 × 10^2 (since 30 × 100 = 3000).Therefore, the statement is arithmetically correct.Verification / Alternative check:Normalize further to strict scientific notation if desired: 3000 = 3.0 × 10^3. Both 30 × 10^2 and 3.0 × 10^3 represent the same value; the latter is preferred when the mantissa is between 1 and 10.
Why Other Options Are Wrong:
- Incorrect: The arithmetic does check out; the equality holds.
- Valid only if units cancel / Cannot be determined: Units are not involved here; it is purely numeric.
Common Pitfalls:Forgetting to align exponents or misplacing the decimal when renormalizing. Always convert to ordinary numbers or match exponents before subtracting.
Final Answer:Correct — 480 × 10^1 − 18 × 10^2 equals 30 × 10^2.