How many significant digits does the number 0.0034 have?

1 Answer
May 19, 2016


Two significant digits (3 and 4)


For zeros, the rule of significant digits can be tricky, but here are the general rules:

#1.# Any zeros before any non-zero digit (which are all significant) are considered to be NON-significant. (The rule used in this example, 0.0034).

#2.# Any zeros between any non-zero digits are SIGNIFICANT
In this case, there are three significant digits: 607

#3.# Any zeros that are to the right of the decimal point and a non-zero number are SIGNIFICANT.
This number contains four significant digits (all the zeros are significant because they come after a non-zero digit and are after the decimal point).

And this notation is not seen as often, but I'll include it anyway:

#4#. If there is a bar above a zero, then that zero is considered significant.

#3bar0 0#
Since the first zero has a bar over it, then this number has two significant digits (the last zero is not a significant digit- there is no bar over it).