Transcript Significant Figures ppt

Significant Figures
Significant Figures
 All measurements are inaccurate
 Precision of measuring device
 Human error
 Faulty technique
Significant Figures
 Measurements need to convey precision
 Must include degree of uncertainty
 Sig Figs tell us
Significant Figures
Significant Figures
1. Significant figures in a measurement
include


all of the digits that are known precisely
plus one last digit that is estimated.
Significant Figures
2. Non-zero digits are always significant.
103.230002
Significant Figures
3. All final zeros after the decimal point are
significant.
12.740
0.0420
Significant Figures
4. Zeros between two other significant
digits are always significant.
10.0
2004
6.000
Significant Figures
5. Zeros used only for spacing the decimal
point are not significant.
100
0.00000233
 Always put a 0 in front of a decimal point

 0.0042 
 .873 
 0.247
Significant Figures
1) 400
2) 200.0
3)
4)
218
5) 320
6)
0.00530
7)
8) 4755.50
0.0001
22 568
Significant Figures
1) 4.0 x 103
2)
1.67 x 10-8
5 x 1012
4)
2.00 x 104
3)
5) 635.000
6) 22 000
7)
8)
5201
81
Significant Figures
6. If you add or subtract, the answer is
rounded to the same number of decimal
places as the measurement with the least
number of decimal places.
Significant Figures
7. If you multiply or divide two numbers,
the answer is rounded off to the number
of significant figures in the least precise
term used in the calculation (i.e. the
number with the fewest sig figs).
Calculations
Calculations