Rules For Significant Figures

1. You can estimate one significant figure past the smallest division on an analog measuring device

2. Every non-zero digit is significantex.24.7 – 3 sig figs

3. Zeros between non-zeros are significantex.24.0007 – 6 sig figs

4. Left most zeros in front of non-zeros are NOT SIGNIFICANTex.0.0099 – 2 sig figs

5. Zeros past a number to the right of a decimal are significantEx.43.00 – 4 sig figs

6. Zeros before understood decimals are NOT SIGNIFICANTex.100 – 1 sig fig

7. Zeros before indicated decimal are significantex.100. – 3 sig figs

8. Counts and exact quantities are infinitely significantex.12 eggs in a dozen5280 ft in 1 mile

9. Adding and subtracting – retain as many places to the right of the decimal as the original number with the least

10. Multiplying and dividing– retain as many significant figures as the original number with the least