The rules for identifying significant figures when writing or interpreting numbers are as follows:
All non-zero digits are considered significant. For example, 91 has two significant figures (9 and 1), while 123.45 has five significant figures (1, 2, 3, 4 and 5).
Zeros appearing anywhere between two non-zero digits are significant. Example: 101.1203 has seven significant figures: 1, 0, 1, 1, 2, 0 and 3.
Leading zeros are not significant. For example, 0.00052 has two significant figures: 5 and 2.
Trailing zeros in a number containing a decimal point are significant. For example, 12.2300 has six significant figures: 1, 2, 2, 3, 0 and 0. The number 0.000122300 still has only six significant figures (the zeros before the 1 are not significant). In addition, 120.00 has five significant figures since it has three trailing zeros.
When you make a measurement using significant figures, you record the numbers you definitely know from the instrument, plus an estimate of the last digit.
The measurement 77.09m has four significant figures.
28.71
6
That measurement has 4 significant figures. It could also be stated as 1.580 x 10^-3.
The accuracy of the measurement device determines the number of significant figures that should be retained in recording measurements.
The significant figures in a measurement include all digits measured exactly, plus one estimated digit.
There are 4 significant figures in this measurement.
There are 3 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 3 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 5 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 3 significant figures in this measurement.