Significant Figures

1. Zeroes between nonzero digits are always significant:
1005 kg (four sig-figs); 7.03 cm (three sig-figs).
2. Zeroes at the start of a number are never significant:
0.02 g (one sig-fig); 0.0026 cm (two sig-figs).
3. Zeroes at the end of a number are significant only if the zeroes are AFTER a decimal point:
0.0200 g (three sig-figs); 3.0 cm (two sig-figs).

Precision vs. Accuracy

Percent Error Calculations