Subject:
The number of significant figures, and thus the precision, of a measurement is determined by the way the measurement is taken. In general, measurements should be reported to one power of ten smaller than the smallest markings on the measuring device. This is done by estimating the last place. For example, when reading a graduated cylinder marked every mL, the position of the meniscus should be estimated to a tenth of a mL. If the meniscus appears to be halfway between the 34 mL and 35 mL markings, then the measurement should be reported as 34.5 mL. All three of these digits are considered to be significant. If however, the measurement is reported as 35 mL, this number has only two sig figs and is less precise.?
