PA_M7_S2_T2_Converting
Units of Volume Transcript
Units of liquid volume are also units that I might want to convert. I
might want to know how many cups are in a gallon or a quart, or how many
ounces are in a pint. I use the same concept of conversion factors I just
have a few more to pay attention to. If I want to go from cups to fluid
ounces, I have 8 fluid ounces per cup. To go the other way, I have 1 cup
for eight fluid ounces. From pints to cups, 2 cups per 1 pint; quarts to
pints, two pints per 1 quart; and gallons to quarts, I have four quarts
to one gallon. The same reciprocal properties for my conversion factors
still apply if I want to go the other direction.
Let's look at some examples. Here I want to change 8.4 quarts to gallons.
8.4 quarts is what I start with and then my conversion factor needs to
have gallons on the top. 1 gallon is 4
quarts, my quarts will cancel and I
divide 8.4 by four and I get 2.1
gallons.
Let's convert 40 fluid ounces to cups. I'm starting with 40 fluid ounces;
I need to go to cups, so I want cups on the top and my fluid ounces on
the bottom. The conversion factor
is that 1 cup is eight fluid
ounces. The fluid ounces would
cancel, I divide eight into 40
and I get 5 cups.
I can do the same thing with pints, or cups, and quarts and back to
gallons and all of that. Let's look at when we might need to use multiple
conversion factors.
If I want to change 5.6 gallons into pints, I start with my 5.6 gallons;
I don't have a direct conversion
from 5.6 gallons to pints so I'm
going to start by converting my
gallons into quart. There are 4
quarts per 1 gallon; this is going to allow me to cancel my gallons. Now
I have quarts, I'm going to want to convert it out of quarts into my
pints. So I have 2 pints per 1 quart. My quarts no w cancel and the only
units I have left are the pints, and I do the multiplication of 5.6*4*2
which is equal to 44.8 pints.
This next one is a little bit different and it's an important one to keep
in mind. I want to go from 4.2 quarts to pounds. Now I'm going from a
volume to a weight and there's a very important conversion that you don't
see in the tables to keep your eye on.
I'm going
to start
with 4.2
quarts;
obviously I
don't have
a direct
conversion
from quarts
to pounds
so I'm
going to
convert my
quarts now
into pints.
If I have quarts on the bottom which is what allows me to cancel, I have
2 pints on the top because there are 2 pints per quart. When I do that,
my quarts cancel and I get 8.4 pints. I still don't have a direct
conversion that I can see between pints and pounds, but I do have
something else I'm going to use. I'm going to convert my pints into
ounces.
One pint is 16 ounces, I'm going to cancel the pints here and what I'm
left with is 8.4*16 ounces which gives me 134.4 ounces. I'm still not to
pounds yet, but now that I'm in ounces, and notice that I've not written
fluid ounces here I've just written ounces, now I have ounces and I can
go back and look at the fact that 1 pound in my weight conversion is
equal to 16 ounces. I divide 16 into 134.4 and I get 8.4 pounds. This
means me to a very important conversion you don't often see in the
tables. That conversion is that 1 pint is 1 pound.
This can help with a lot of conversions if I'm talking about volume
measurements especially for dry volume, flour that I need in a recipe and
knowing how many pounds of flour I need to buy in order to create a
recipe that takes multiple cups of flour.
So these are important conversions to keep in mind and this pint being
equal to a pound is one to put in your back pocket.