1. 8
Significant
Figures

2. Significant figures
The number of meaningful digits in a measurement including the uncertain digit.
“sig figs”
0.520
0.0025
500
120035
500.
2.0 x 105
3 do not count zeros at the beginning 2
1 do not count end zeros if no decimal
4 count all other zeros 6 3
2 do not expand

3. Significant figures
The number of meaningful digits in a measurement including the uncertain digit.
“sig figs”
2.5002
5001
200
200.
2.0 x 102
2. x 102 5 3 4 6 4 1 3 2 1

4. Significant figures
Exact numbers that are counted or defined and not measured have zero uncertainty and infinite “sig figs”.
“sig figs”
2.50 cm
3 girls
62.33 kJ
1 cm = 10 mm
12.3 oC
200 lb
1 cm3 = 1 mL
$75.00 3
infinite 4
infinite 3 1
infinite
infinite

5. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used. 1.
21.036
+ 22.1

6. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used 1.
21.036
+ 22.1??

7. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used. 1.
21.036
+ 22.1??
= the largest decimal place is the first

8. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used 2.
25.654
- 22.1?? =

9. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used 2.
25.654
- 22.1??
= the largest decimal place is the first

10. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used 3.

11. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used 3.
the largest decimal is the second

12. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used 4.
x 107
+ 2.3 x 104

13. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used.
↓ largest decimal place x
+ 2.3 x

14. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used.
↓ largest decimal place x
+ 2.3 x x

15. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used. 5.
x 10-5 x

16. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used. 5. x x
↑ largest decimal place

17. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used. 5. x x
5.008 x largest decimal place

18. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used. 6.
x 10-4 x

19. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used.
↓ largest decimal place x x

20. Adding and Subtraction with Significant Figures
When adding or subtracting numbers round the answer to the largest decimal place found in the uncertain digits of any of the numbers used.
↓ largest decimal place x x x

21. 7. Add the two numbers- another way to do itx x x x x
Change the lower exponent to the higher and write it directly underneath.
You are making the exponent larger so make the number smaller.

22. 8. Subtract the two numbers- another way to do it
x 1018
x 1015
x 1018
x 1018
x 1018
Change the lower exponent to the higher and write it directly underneath.
You are making the exponent larger so make the number smaller.