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# U.S. customary units: fluid volume

CCSS.Math:

## Video transcript

let's do a survey about how we would measure the volume of fluids under 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 someone you'll talk about a teaspoon 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 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 in your cabinets in your kitchen at home so this is might be a teaspoon right over here now if you were to take three 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 is right over here is a teaspoon this right over here is a teaspoon of some stuff since if you multiply that by three then you get to the tablespoon table tablespoon so three teaspoons equal one tablespoon so a tablespoon is going to be a little bit bigger so tablespoon might look like this and these are the bigger 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 three times the fluid you get to a tablespoon now if you take two tablespoons you take two tablespoons put them together then you get to the ounce and I have to be careful here you get to the fluid ounce 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 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 two tablespoons or as we'll see one eighth of a cup now you might say well why are they both called ounces what's the relationship between the two well there is a somewhat of a relationship between the two if you took a little bit over an a 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 so an ounce of water and a fluid ounce a fluid ounce of what an ounce of water and weight and a fluid ounce of water and volume are very very very close although they aren't exactly the same thing now if you were to take and you know 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 two tablespoons which would be equivalent to a fluid ounce now if you take eight fluid ounces and put them together so let me make let me draw a fluid ounce here just look like we keep we 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 that might be you do two tablespoons in it maybe that'll be the fluid ounce now if you take eight fluid ounces if you take eight fluid ounces then you get to a cup 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 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 canna soda the typical canna 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 eight fluid ounces a typical can of soda is 12 fluid ounces so it is equivalent it is equivalent to a cup and a half let make sure this looks like a can of some kind so this if this was 12 ounces this is 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 two cups if you were to take 2 cups now you're dealing with now you're dealing with a pint and so you might have seen pints a pint might look sometimes they're these kind of 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 two cups and so let's say this is a fluid inside of it let's say this was transparent you might see it there or if you have like a very large mug that might be the size of a pint so if you have a kind of a very large a very large mug like this so my best attempt at drawing a large mug this might be roughly roughly equal 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 two pints you take two pints now you're 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 those longer but still kind of skinny skinny looking so it might look it might look something like this I'm trying to draw make a carton of a quart of milk and then finally if you were to take if you were to take four quarts together you get to a gallon so you take four quarts together so times four you get to a gallon 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 at well I'm sure someone can draw a better gallon of milk here but you've it's at least in the US it tends to be one of the most difficult ways that they sell they sell the milk and has oftentimes a little red or orange thing right on top there so a gallon of milk so just to review things and if we want to think you know 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 a cup right over here is equal to so this is going to a cup is going to be equal to eight ounces eight ounces is equal to a cup if you multiply that by two then you get to 16 ounces is equal to a pint if you multiply that by two 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 128 128 ounces per gallon and so next time you go buy something in the supermarket I encourage you to look at it what how it's being measured and you'll see often times you might buy a quart of milk what they'll also say that this is a 32 ounce container and in this context they're talking about fluid ounces