1. Significant Figures

2. What are Significant Figures (Sig Figs)?
The places in the number that are important.
This will tell you how accurate a measurement is.
There are a few rules to help you figure out how many sig figs there are in a number.

3. Activity
You and your partner will make up your own rules for determining sig figs.
The steps are as follows
read all of the numbers through
brainstorm (no discussion/ critique)
discuss/ critique
write a concise rule

4. Example
Red 3
Fire House 9
Teach 5
July 4
Frisbee 7

5. Example Red 3 letters Fire House 9 letters Teach 5 letters
July 4 letters
Frisbee 7 letters

6. Example Rule
The number of letters in the word is the number.

7. First Rule 5426 4 sig figs 8.235 4 sig fig 19 2 sig figs 7 1 sig fig

8. Rule
All real numbers (1-9) count as a significant number, the decimal does not matter

9. 2nd Rule 102 3 sig figs 20003 5 sig figs 34509 5 sig figs

10. 2nd Rule
All zeros that are in between two significant figures are significant.

11. 3rd Rule 0.00045 2 sig figs 0.0123 3 sig figs 0.00123 3 sig figs

12. 3rd rule
Leading zeros that are placeholders are not significant

13. 4th rule 7600 2 sig figs 1000000 1 sig figs 560 2 sig figs

14. 4th rule
All zeros following a number are not significant if they are a placeholder.

15. 5th rule 7600. 4 sig figs 1250. 4 sig figs 1000. 4 sig figs

16. 5th rule
Zeros are significant if they are between a number an a decimal place (i.e. not a placeholder)

17. 6th rule 0.0090 2 sig figs 0.0001200 4 sig figs 0.120 3 sig figs

18. 6th rule
Final (ending) zeros after a decimal are significant

19. Applying your rules 520.36 ? sig figs 1.00250 ? sig figs 60 ? sig figs

20. Applying your rules 520.36 5 sig figs 1.00250 6 sig figs 60 1 sig figs