Significant Figures

2. Significant Figures

3. What do you write? 6.2 5.45

4. What do you write? 6.2 = 1.1376146… 5.45

5. Precision - Accuracy -

6. Precision - how exact a measurement it Accuracy -

7. Precision - how exact a measurement it Accuracy - how close the measurement is to the true value

8. Precision - how exact a measurement it Accuracy - how close the measurement is to the true value

9. Precision - how exact a measurement it Accuracy - how close the measurement is to the true value

10. Significant Figure

11. Significant Figure • The digits in a measurement that you know with certainty

12. Significant Figure • The digits in a measurement that you know with certainty • Includes one “doubtful digit”

13. Rules for Counting Significant Figures 1. All non-zero digits are significant. Example: 123.7 has 4 significant figures 2. All zeros between non-zero digits are significant. Example: 1207 has 4 sig. figs., 120.007 has 6 sig. figs. 3. All zeros at the left of the number are NOT significant. Example: 0.00032 has 2 sig. figs, 0.03 has 1 sig. fig. 4. When zeros are at the right of the number: a) If there is no decimal, the zeros are NOT significant. Example: 300 has 1 sig. fig., 25400 has 3 sig. figs. b) If there is a decimal, the zeros ARE significant. Example: 60.0 has 3 sig. figs., 0.00045300 has 5 sig. figs. (the 4 zeros at the left of the number do not count, but the 2 zeros at the right of the number do count).

14. Rules for calculating with sig. figs.

15. Rules for calculating with sig. figs. multiply/divide 6.2 = 1.1376146… 5.45

16. Rules for calculating with sig. figs. multiply/divide 6.2 = 1.1376146… 5.45 • Count the number of sig. figs. in each measurement

17. Rules for calculating with sig. figs. multiply/divide 6.2 = 1.1376146… 5.45 • Count the number of sig. figs. in each measurement • The answer has as many as the least precise measurement (fewest)

18. Rules for calculating with sig. figs. multiply/divide 6.2 = 1.1376146… 5.45 • Count the number of sig. figs. in each measurement • The answer has as many as the least precise measurement (fewest) • Use the last digit dropped to round

19. Rules for calculating with sig. figs. multiply/divide 6.2 = 1.1 5.45 • Count the number of sig. figs. in each measurement • The answer has as many as the least precise measurement (fewest) • Use the last digit dropped to round

20. Rules for calculating with sig. figs. add/subtract 14.3 + 220.75 235.05

21. Rules for calculating with sig. figs. add/subtract 14.3 + 220.75 235.05 • Keep everything to the left of the decimal

22. Rules for calculating with sig. figs. add/subtract 14.3 + 220.75 235.05 • Keep everything to the left of the decimal • Keep only the places in common to the right of the decimal

23. Rules for calculating with sig. figs. add/subtract 14.3 + 220.75 235.05 • Keep everything to the left of the decimal • Keep only the places in common to the right of the decimal • Use the last digit dropped to round

24. Rules for calculating with sig. figs. add/subtract 14.3 + 220.75 235.05 = 235.1 • Keep everything to the left of the decimal • Keep only the places in common to the right of the decimal • Use the last digit dropped to round