Answer
The volume of total fresh water on earth is 3.73 x $10^{17}$ $m^{3}$ or expressed in litters it is 3.73 x $10^{20}$ L
Work Step by Step
1- Step one 3.73 x $10^{8}$ km3 to be expressed into m3.
We know that 1 km = $10^{3}$ m.
So 1 $km^{3}$ = $(10^{3})^{3}$ $m^{3}$
1 $km^{3}$ = $10^{9}$ $m^{3}$
The total amount of fresh water on earth: 3.73 x $10^{8}$ km3 = 3.73 x $10^{8}$ x $10^{9}$ m
So the volume of total fresh water on earth is 3.73 x $10^{17}$ $m^{3}$
2 Step two 3.73 x $10^{17}$ $m^{3}$ to be expressed into dm3 (or as it is known better in Liters). Rememeber 1L = 1dm3
1 m equal $10^{1}$ dm
1 $m^{3}$ = $(10^{1})^{3}$ $dm^{3}$
3.73 x $10^{17}$ $m^{3}$ = 3.73 x $10^{17}$ x $10^{3}$ $dm^{3}$
3.73 x $10^{17}$ $m^{3}$ = 3.73 x $10^{20}$ $dm^{3}$ = 3.73 x $10^{20}$ L
