1. SIGNIFICANT FIGURES

2. All non-zero digits are significant. 13,438 - 75 - 24.45 - 5 2 4
The following rules apply when determining the number of significant digits:
All non-zero digits are significant.
13, 5 2 4
2. Any zeros between nonzero digits are significant.
12, 5 4 4
3. All final zeros to the right of the decimal are significant. 3 3 4
4. Zeros as place holders are not significant.
27, 2 1 2
A decimal point placed after zeros indicates they are significant. 3 2 4
5. There two situations in which numbers have an infinite number of sig figures.
a) counting numbers: 23 people, 2 dozen, 3 moles.
b) defined quantities (SI) : 100 cm, 60 sec, 1000 mg

3. 5
How many sig figs? g
Which digit
is estimated?

4. 265.73 g 171. g 4 8 5 The number of significant digits
depends on the instrument used.
The last digit is always estimated. g 4 8 5

5. WHITEBOARD
PRACTICE

6. 20 1

7. 40. 2

8. 8000 1

9. 900. 3

10. 9009 4

11. 1

12. 120 2

13. 808 3

14. 0.002 1

15. 92,000 2

16. 395,000. 6

17. 12,080 4

18. 0.8 1

19. 1

20. 2

21. 1.0400 5

22. 22,000,100 6

23. 0.7000 4

24. 3.0000 5