1. Significant Figures

2. Which is more precise? .00700 or 7.00

3. First we need to understand significant figures
A helpful trick involves a little geography…
-Note where the Atlantic and Pacific Oceans are...

4. If the decimal is Present, count from the Pacific side, starting with the first non-zero
How many Sig figs are in each of the following numbers?
9.083
9.9990
0.1830
.00700
Pacific Ocean
4 sig figs
5 sig figs
3 sig figs

5. If the decimal is Absent, start counting digits from the Atlantic side, starting with the first non-zero digit
How many Sig figs are in each of the following numbers?
9000
99099
183
7001
1 sig figs
5 sig figs
3 sig figs
4 sig figs
Atlantic Ocean

6. So which is more Precise .00700 or 7.00?
Hint: Which has more Sig Fig’s
It’s the same!
Both have 3 Sig figs
It may help to think of it with units
Km is the same as 7.00 m

7. How many Sig Figs are in...
.900
900
1001
.001
3 Sig figs
1 Sig Fig
4 Sig Fig

8. How do we know how many sig fig’s to use when we are measuring?
You can go one place beyond the instrument.
For example: This ruler marks every .001 meters
We can go to meters

9. What happens when you Add, Subtract, multiply and Divide Sig Figs?

10. Addition and Subtraction of Sig Figs...
Count the number of sig figs in the decimal portion ONLY
Add or subtract
Round to the LEAST number of decimal places found in the problem

11. mL mL mL
5.157 m m m mL
10.73 mL m
10 m

12. Multiplication and Division
A number is no more precise than the least precise value (a chain is only as strong as weakest link)
Determine the number of Sig Figs for each number in the problem
What is the least amount of Sig Figs? This is how many sig figs your answer should have

13. 7.750 g
5.4 mL
23.587g
32.5mL
= g/mL
= 1.4 g/mL
= g/mL
=.726g/mL