Question

The value of the measurement \(14.0 \times 10^{-5} + 8.3 \times 10^{-3}\) with respect to significant figures is.

• A. $8.4\times10^{-3}$
• B. $8.314\times10^{-3}$
• C. $2.43\times10^{-3}$
• D. $8.44\times10^{-3}$
• E. $8.440\times10^{-3}$

Hint:

Align the exponents first before applying addition/subtraction rules.

Answer 1

The Correct Option is A

Step 1: Concept
Rules for addition with significant figures and scientific notation.

Step 2: Meaning
Convert both to the same power: $0.14 \times 10^{-3} + 8.3 \times 10^{-3} = 8.44 \times 10^{-3}$.

Step 3: Analysis
In addition, the result must have the same number of decimal places as the measurement with the fewest decimal places. $8.3 \times 10^{-3}$ has one decimal place.

Step 4: Conclusion
Rounding $8.44 \times 10^{-3}$ to one decimal place gives $8.4 \times 10^{-3}$.
Final Answer: (A)