Transcript Mesurements

Significant figures
Scientific Notation
Dimensional analysis

In the real world, no measurement is
exact. The relative exactness of a
measurement is its accuracy

In a measured value, all the digits that
are known to be exact are called
significant digits. Zeros at the end of a
whole number are assumed to be nonsignificant.
Rule
Example
1.) Every non zero number
is significant
a.) 22
b.)45.7
a.)
b.)
a.) 1,001
a.)
b.) 78, 002
b.)
a.) 0.00400
a.)
b.) 0.01000
b.)
a.) 0.0032
a.)
b.) 0.000005
b.)
a.) 1,000. -measured
a.)
b.) 300.-not measured
b.)
2.) Zeros between non
zero digits are significant
3.) Zeros at the end of the
number and to the right of
the decimal are significant
4.) Zeros appearing in
front of non zero digits are
not significant
5.) Zeros at the end of the
number, but to the left of
the decimal are significant
if they have been
measured
Number of Significant
Figures
1.
2.
3.
4.
5.
9004507 m has ___ significant figures
0.00000860092 s has __ sig. figs.
102.00 kg has ___ sig. figs.
The ruler reads 700 g, so your measurement
has ___ sig. figs.
1.02 x 105 s has ___sig. figs.

Used for very large or very small numbers.

Made up of three parts: the coefficient, the
base and the exponent.
567 000 in sci. notation is:
5.67 x 105
coefficient
base
exponent

Move decimal as many times to make a number between 1
and 10

Coefficient is always followed by x 10

Exponent = number of times you move the decimal
 Large # = ( + )exponent
 Small # = ( - )exponent

Example: What is 238,000 in Sci. Notation?
1)
597800000
2)
0.00004507
3)
2500000000
4)
0.0023

Move the decimal as many times as the
exponent is worth
 Positive exponent = move to the 
 Negative exponent = move to the 

Fill spaces with zeros

Example: What is 1.56 x 105 in Standard
notation?
1)
2.36 x 108
2)
7.8 x 10-3
3)
3.92 x 10-5
4)
5.43 x 105

It is a method used to convert from one unit to
another

Consists of 3 Steps to get your answer
 1.) Identify the Given and the Unknown
 2.) Identify the Conversion factor needed to go from
one unit to another
 3.) Set up the problem
 4.) Multiply across at the top and divide by the bottom

How many kg are in 3.42 grams?

500 ft = ______________________ m

5750 mL= _________________ L

0.024 km= __________________m

432 minutes = ________________ hrs