1.  Significant Figures

2. So Many Numbers  How many places do you carry out?  What do we round to?  These are no longer acceptable questions for the science classroom!!!

3. What numbers are important?  Sig Figs are used in science because of measurement  Numbers must be:  Meaningful  Accurate  Be confident in the numbers you use  Measurement tools help identify sig figs

4. Rules to Follow  Non-zero digits are always significant  Any zeros between two significant digits are significant  A final zero or trailing zeros in the decimal portion ONLY are significant

5. A Few Examples  34.84

6. A Few Examples  34.84 (4 sig figs)  3001

7. A Few Examples  34.84 (4 sig figs)  3001 (4 sig figs)  100.00

8. A Few Examples  34.84 (4 sig figs)  3001 (4 sig figs)  100.00 (5 sig figs)  497,000,000

9. A Few Examples  34.84 (4 sig figs)  3001 (4 sig figs)  100.00 (5 sig figs)  497,000,000 (3 sig figs)  405.00750

10. A Few Examples  34.84 (4 sig figs)  3001 (4 sig figs)  100.00 (5 sig figs)  497,000,000 (3 sig figs)  405.00750 (8 sig figs)

11. Non-contributing Zeros  Some zeros are not meaningful, accurate, or important  They are simply placeholders and are not significant figures

12. Insignificant Zeros  Space holding zeros on numbers less than one  0. 0 2750  0. 0000 4  0. 00 8035

13. Meaningless Zeros  The zero to the left of the decimal place on numbers less than one  0.005  0.9867  00.004208

14. Loser zeros  Trailing zeros in a whole number  2 00  54 0  1 0,000

15. Pointless Zeros  Leading zeros in a whole number  00 365  00 4.0 x 10 -6  00 250

16. Adding and Subtracting  Determine which number has the fewest significant figures  Your answer can only have the significant figures equal to the fewest sig figs in a problem  Only as strong (confident) as the weakest link

17. Adding and Subtracting  2.97 + 0.11 =  0.4006 + 35.1 =  7.2398 + 0.01 =

18. Multiplying and Dividing  Determine which number has the fewest significant figures  Your answer can only have the significant figures equal to the fewest sig figs in a problem  Only as strong (confident) as the weakest link

19. Multiplying and Dividing  5.4 x 3.75 = .0027 x 87.21 =  21 x 3 =

20. Why Sig Figs?  Measurement and accuracy of our tools  Replication  Confidence  Meaningful

21. You are now Sig Fig experts!