Significant digits

Definition

Significant digits (or significant figures) represent the meaningful digits in a measured or calculated quantity, reflecting its precision. They indicate the accuracy of a number by showing which digits are known reliably.

5 Must Know Facts For Your Next Test

1. All non-zero digits are considered significant.
2. Any zeros between significant digits are also significant.
3. Leading zeros are not considered significant as they only serve as placeholders.
4. Trailing zeros in a number containing a decimal point are considered significant.
5. In multiplication and division, the result should have the same number of significant digits as the measurement with the fewest significant digits.

Review Questions

• How many significant digits are in the number 0.00456?
• When multiplying 3.24 and 0.086, how many significant digits should be in the final answer?
• Why are trailing zeros without a decimal point not considered significant?

Related terms

Measurement Uncertainty: The doubt that exists about the result of any measurement, often expressed as a range of values.

Accuracy: Refers to how close a measured value is to the true or accepted value.

Precision: $\text{Refers to the consistency or repeatability of measurements, indicating how close multiple measurements are to each other.}$