Which statement about significant figures is true?

Which statement about significant figures is true?

• A. They show the number of digits in the measurement.
• B. They are only about decimal numbers.
• C. They indicate both precision and uncertainty in a measurement.
• D. They specify the instrument's manufacturer.

Answer: (C)

Significant figures show how precise a measurement is and where its uncertainty lies. Each digit reported is known with confidence, and the last digit represents an estimate. That combination means the number of significant figures communicates both the precision of the measurement and the size of the uncertainty in the final digit. For example, writing a length as 12.3 cm signals precision to the tenths place, with that last digit (the 3) reflecting uncertainty of about ±0.1 cm. This concept applies to any measured quantity, not just decimal numbers, and it doesn’t tell you anything about the instrument’s manufacturer.

Significant figures show how precise a measurement is and where its uncertainty lies. Each digit reported is known with confidence, and the last digit represents an estimate. That combination means the number of significant figures communicates both the precision of the measurement and the size of the uncertainty in the final digit. For example, writing a length as 12.3 cm signals precision to the tenths place, with that last digit (the 3) reflecting uncertainty of about ±0.1 cm. This concept applies to any measured quantity, not just decimal numbers, and it doesn’t tell you anything about the instrument’s manufacturer.