Significant figures
0.0093: Leading zeros are never significant. This number has two significant figures, nine and three.
120.9: Nonzero numbers are significant and zeros between those numbers are significant, too. This number has four significant figures.
1.000: Trailing zeros are significant if there is a decimal point. This number has four significant figures.
1.008: Nonzero numbers are significant and zeros between those numbers are significant, too. This number has four significant figures.
670: Trailing zeros are not significant. This number does not have a decimal point. So, it has two significant figures.
0.184: Nonzero numbers are significant. This number has three significant figures.
1.30: Trailing zeros are significant if there is a decimal point. This number has three significant figures.