What are significant digits?

Significant digits, also known as significant figures, are the digits in a number that contribute to its precision and accuracy. These digits include all non-zero numbers, zeros between significant digits, and trailing zeros in a decimal fraction. The concept is fundamental in engineering and science because it conveys how precise measurements and calculations are. For instance, if a measurement is reported as 5.30, it indicates not only the value but also the confidence in the measurement, suggesting that the measurement is precise to two decimal places.

The other options do not accurately capture the definition of significant digits. For example, while some numbers may be rounded for simplicity, that does not directly relate to the idea of significant digits, which focuses on the digits that carry meaningful information about precision. Additionally, digits that do not contribute to precision are not considered significant; therefore, the exclusion of certain digits does not denote their significance. Lastly, significant digits are not limited to whole numbers; they can include decimal numbers, making the option regarding digits being whole numbers incorrect.