Let’s do a survey about

how we would measure the volume of fluids

under US customary units. So the smallest volume of

fluid that you’ll hear people talk about– and this will

often be in cooking recipes or something like this–

you’ll talk about a teaspoon. And most of us have

teaspoons that are roughly the size of a teaspoon in

our cupboards someplace. So this recipe might call

for a teaspoon of sugar, or a teaspoon of salt,

or a teaspoon of oil. And you’ve seen

what it looks like. But those are the

smaller spoons that you might have in your cabinets

in your kitchen at home. So this might be a

teaspoon right over here. Now, if you were to take

3 teaspoons together, you have something else

that you would probably have in your cabinets. So if we multiply

this volume, so let’s say this right

over here is a teaspoon. This right over here is a

teaspoon of some substance. If you multiply that by 3,

then you get to the tablespoon. So 3 teaspoons

equal 1 tablespoon. So a tablespoon’s going

to be a little bit bigger. So a tablespoon

might look like this. These tend to be about the

size of the larger spoons that you have in your

cupboard, so a tablespoon, just like that. So if you have 3 times the

fluid, you get to a tablespoon. Now, if you take 2

tablespoons, put them together, then you get to the ounce. And I have to be careful here. You get to the fluid ounce. And the US customary units, they

aren’t designed to be super, super clear. Because you also have the

ounce as a measure of weight. You have the ounce that

is a measure of weight, which is equal to

1/16 of a pound. And now you have a fluid

ounce, which you could either view as 2 tablespoons or,

as we’ll see, 1/8 of a cup. Now, you might say, well, why

are they both called ounces? What’s the relationship

between the two? Well, there is somewhat of a

relationship between the two. If you took a little bit

over an ounce of water, so a weight of ounce

of water, slightly over an ounce of

water, that volume is going to be

about a fluid ounce. An ounce of water in

weight and a fluid ounce of water in volume are

very, very, very close, although they aren’t

exactly the same thing. Now, if you think about,

what would you measure here? We already talked about recipes,

and teaspoon, tablespoon, fluid ounce. You might be thinking

about how much medicine maybe someone might take. Maybe they need to take

2 tablespoons, which would be equivalent

to a fluid ounce. Now, if you take 8 fluid ounces

and put them together– so let me draw a fluid ounce here

just so we still have drawings. So you could imagine

some medicines have a little cap on the top that

you could put the medicine in. So if you do 2

tablespoons in it, maybe that will

be a fluid ounce. Now, if you take 8 fluid

ounces then you get to a cup. And many of us have

this in our kitchens. We have a measuring cup that

will measure exactly a cup. And you might have a

recipe for pancakes that say, hey, put a

cup of flour in there. And also a lot of the cups

that you have in your house might be around might be

around the size of a cup. If you look at,

say, a can of soda that you’re probably

familiar with, a can of soda, the typical can of soda,

is 12 ounces, not 8 ounces. So a typical can of soda

is a cup and a half. We see that a cup

is 8 fluid ounces. A typical can of soda

is 12 fluid ounces. So it is equivalent

to a cup and a half. Let me make sure this looks

like a can of some kind. So if this was 12 ounces,

this is 1 and 1/2 cups. But it gets you a sense of

how much fluid volume a cup actually is. Now, if we were to take 2 cups,

now you’re dealing with a pint. And so you might

have seen pints. Sometimes they’re in

these small cartons. So a pint might look something

like this in a carton. That looks more like a house. But I think, hopefully,

you get the picture that this is intended to

be a carton of some kind. So you have something like that. And so the pint, it’s 2 cups. And so let’s say this is

the fluid inside of it. Let’s say this was transparent,

and you might see it there. Or if you have a

very large mug, that might be the size

of a pint, so if you have a very large mug like this. So my best attempt at

drawing a large mug, this might be roughly

equal to a pint. So let me put some

fluid in here. So there you go. There’s my large mug. It’s got a pint. Now, if you take 2 pints, now

you are dealing with a quart. And you might have

found yourself going to your local

convenience store and buying a quart of milk. A quart of milk, those are kind

of those longer but still kind of skinny looking– so it

might look something like this. I’m trying to draw a

carton of a quart of milk. And then finally, if you were

to take 4 quarts together, you get to a gallon. So you take 4 quarts

together– so times 4– you get to a gallon. So we’re most familiar

with a gallon of milk. So let me see if I can

draw a gallon of milk here, my best attempt. Well, I’m sure someone could

draw a better gallon of milk here. But at least in the

US, it tends to be one of the most typical

ways that they sell milk. And it has, oftentimes, a

little red or orange thing right on top there,

so a gallon of milk. So just to review things,

right here, I just multiplied from the smaller

unit to the larger one. But if you want to think about

everything in terms of ounces, that’s one way to

think about it. A cup right over here

is equal to 8 ounces. 8 ounces is equal to a cup. If you multiply that by 2,

then you get to 16 ounces is equal to a pint. If you multiply that by

2, you get 32 ounces. 32 ounces is equal to a quart. And if you multiply

that times 4, you get 30 times

4 is 120, plus 8. You get 128 ounces per gallon. And so next time you go buy

something in the supermarket, I encourage you to look at

how it’s being measured. And you’ll see that oftentimes

you might buy a quart of milk, but they’ll also say that

this is a 32-ounce container. And in this context, they’re

talking about fluid ounces.

now i get it

thank you

Thank You!

Great source!

you're really helping me in math

THANKS!!!!!