1. Significant Figures

2. Significant Figures All measurements are inaccurate
Precision of measuring device
Human error
Faulty technique

3. Significant Figures Measurements need to convey precision
Must include degree of uncertainty
Sig Figs tell us

4. Significant Figures

5. Significant Figures Significant figures in a measurement include
all of the digits that are known precisely
plus one last digit that is estimated.

6. Significant Figures
2. Non-zero digits are always significant

7. Significant Figures
3. All final zeros after the decimal point are significant

8. Significant Figures
4. Zeros between two other significant digits are always significant

9. Significant Figures
5. Zeros used only for spacing the decimal point are not significant

10. Always put a 0 in front of a decimal point 
.873 

11. Significant Figures 1) 400 2) 200.0 3) 0.0001 4) 218 5) 320 6) 0.00530
1)   400  
2)    200.0
3)   
4)    218
5)  320  
6)   
7)   
8)  

12. Significant Figures 1) 4.0 x 103 2) 1.67 x 10-8 3) 5 x 1012
5) 
6)  
7)    5201
8)    81 

13. Significant Figures
6. If you add or subtract, the answer is rounded to the same number of decimal places as the measurement with the least number of decimal places.

14. Significant Figures
7. If you multiply or divide two numbers, the answer is rounded off to the number of significant figures in the least precise term used in the calculation (i.e. the number with the fewest sig figs).

15. Calculations

16. Calculations