1. 4 Units Clarify Sig. Figs.

2. We have seen how to convert a measurement from one unit to another.
In these conversions zeros are lost or gained.
Zeros which can be lost or gained in unit conversions are not significant.
For example, how many centimeters are in 2.3 meters?
For another example, how many meters are in 23 millimeters?
What is the unit in the numerator of the unit factor?
What are the factors?
How many significant figures are in 2.3 m?
And the final answer is?
How many significant figures are in 230 cm?
And the zero at the end of the number?
And the answer is?
What is the unit in the denominator of the unit factor?
What are the factors?
Shall we try the same quick method?
And the zero at the beginning of the number?
What unit goes in the denominator of the first unit factor?
So, how many significant figures in .023 m?
How many significant figures in 23 mm?
So, what unit goes in the numerator of the first unit factor?
There is only one measurement and it has two sig. fig.
It does not matter if the measurement is written as 23 mm or .023 m
It is not significant
Again just two.
We shall
Just two
It is not significant.
But see if you can construct the unit factors
as you write the equation.
Again just two. We can not gain accuracy
merely by changing the units of the measurement.
Just two.
Follow the standard method.
( )
2.3 m
100 cm
= cm
230 1 m
( ) 1 m
23 mm
= m
.023
1000 mm