General Rules for Determining Number of Significant Figures

1. All nonzero digits are significant.

2. Zeros are also significant with two exceptions:

   1. zeros preceding the decimal point.

   2. zeros following the decimal point and preceding the first nonzero digit.

3. Terminal zeros preceding the decimal point in amounts greater than one is an ambiguous case.

Rules for Numbers WITHOUT a Decimal Point

1. START counting for sig. figs. On the FIRST non-zero digit.

2. STOP counting for sig. figs. On the LAST non-zero digit.

3. Non-zero digits are ALWAYS significant.

4. Zeroes in between two non-zero digits are significant. All other zeroes are insignificant.