How do you determine the number of significant figures in a measurement?

To determine the number of significant figures in a measurement, one must consider all the digits that contribute to its precision. This includes all non-zero digits, zeros that are sandwiched between non-zero digits, and any trailing zeros that are to the right of a decimal point.

For example, in the measurement 0.00430, the leading zeros are not counted as they do not affect the measurement's precision. The significant figures here are 4, 3, and the trailing zero, as they indicate that the measurement is precise to that last decimal place. Thus, this measurement has three significant figures.

By recognizing both the importance of the non-zero digits and the role that certain zeros play in establishing the precision of a measurement, one can accurately account for all significant figures present. Therefore, the comprehensive approach to counting all relevant digits justifies the choice as the correct method for determining significant figures.