Measurement reporting: The digits in a measured value that are certainly known (plus the properly estimated final digit) are called:
-
Aaccuracy digits
-
Bsignificant digits
-
Cerror digits
-
Dprecision digits
Answer
Correct Answer: significant digits
Explanation
Introduction / Context:In experimental work and instrument reading, communicating how trustworthy a number is matters as much as the number itself. Significant digits (also called significant figures) encode the certainty of a measurement and the resolution of the measuring instrument, guiding rounding and propagation of uncertainty in calculations.
Given Data / Assumptions:
- A measured value includes digits known with certainty and one last digit that is an estimate.
- We use standard conventions for counting significant digits.
- Terms like accuracy and precision have specific meanings distinct from significant digits.
Concept / Approach:Significant digits are all nonzero digits, zeros between nonzero digits, and trailing zeros in a decimal number; leading zeros are not significant. They reflect measurement resolution and should be preserved through calculations according to established rules for addition/subtraction and multiplication/division to avoid overstating certainty.
Step-by-Step Solution:
Identify the certain digits based on instrument scale or display.Include one estimated digit (the smallest division you can read).Label the total set as the significant digits of the measurement.Verification / Alternative check:Cross-check with instrument specifications: if a digital multimeter is 3.5 digits, its last displayed digit is the least significant and often the estimated/uncertain one, consistent with significant-digit rules.
Why Other Options Are Wrong:
- Accuracy digits/precision digits: Accuracy and precision are performance qualities, not names for the digits themselves.
- Error digits: There is no such standard term; error relates to uncertainty, not a specific set of digits.
Common Pitfalls:Carrying too many digits through computations (false precision) or rounding too early, which can distort results. Round at the end, respecting the weakest measurement's significant digits.
Final Answer:significant digits