Number of digits in a figure that express the precision
of a measurement
instead of its magnitude
. In a measurement, commonly the in-between (embedded) zeros are included but leading and trailing
zeros are ignored. Non-zero digits, and leading zeros to the right
of a decimal point, are always significant
. For example, the figure 239.80 has four significant digits, 925,000 has three, and 0.030677 has six.