Statistics and Significant Figures

Hence, in the above case, there are three significant figures, where the first two digits are certain (37 mm) and the last digit (0.2 mm) is uncertain.

Here are some guidelines for significant figures concerning zeros:

A. Zeros that locate the decimal place are not significant. For example, 0.0053 has two significant digits. A good way to make the number of significant figures clear is by using scientific notation. The previous example would be 5.3 x 10-3 in scientific notation. Notice how scientific notation only shows significant figures.

B. Zeros that are surrounded by other digits are significant in all cases. For example, 2.4308 x 1034 has a significant zero between the '3' and the '8.'