this video is on systems of measurement so every measurement that you make or that you read or that you have consists of a number and a unit so there's different systems so there's the English system which is what we use in the United States uh we use gallons to the volume of something we use pounds for the mass of something and then there's a metric system metric system is used in medicine and science and then lastly there is the SI system which is an international system and that's based off of the metric system so here in America we actually do use the metric system sometimes if you think of track and field one lap around the track it's called the 400 meter meter is metric or if you go to the store and buy a 2 L bottle of soda leaders is metric so we do use it even though you may not recognize it or realize it so here are the base units in the metric system so anytime we're working with length we will use the base unit of meter now we will see that you can convert to smaller units or larger units but anytime we have length it will be meter anytime we're working with mass it will be grams volume will be liters and then time which we are familiar with will be seconds there are many prefixes which you will have to know and memorize that go along with the base units so on the larger scale you have Tera Giga and mega and I would actually put kilo here as well that's a lowercase k and notice the difference is the number of zeros you have your scientific notation part here with the exponent just being the number of zeros and then you have the expanded form right here you are just moving the decimal point to go from one unit to the other and then on the smaller scale you have if we're using meters for example you have a decimeter a centimeter a millimeter a micrometer a nanometer there are picometers and it does get smaller and smaller and smaller it's very convenient to know the different prefixes because you can eliminate some zeros and some really small decimal points or some really big numbers so for example if you're looking at the diameter of a drop of blood on the head of a pin you can say that that is 0.001 M or to clean it up a little bit you can say that is 1 mm I think it is way easier way cleaner to get rid of those zeros and just say 1 mm if you need a visual of what a millimeter looks like if you can picture a meter stick it is just one of those little lines on a meter stick there are a thousand mm in one meter as we get smaller the diameter of a blood cell is 0000001 M or if we talk in terms of micrometers that would just be one micrometer a micrometer is a thousand times smaller than a millimeter and you can see that up here micro is 1 * 10 -6 and Millie is 1 * 10 -3 so notice there's a difference of three there which is just three zeros so a th000 this would be a th000 * smaller this would just be since it's only difference of one Zer that would be 10 times bigger a centimeter is 10 times bigger and then a decimeter again there's only one difference between here and here so that's a factor of 10 as well and then memory of a hard drive you could say that's 1 billion bytes or just one terabyte here is a line timeline if you will not really a timeline but of all the different prefixes so I wrote out what they actually are called up here and then beneath them I wrote down their abbreviation so these are the ones that you should be familiar with so if we Orient ourselves here these are our base units so if you want to consider this as like a one here so we have grams we have meters we have liters and we have seconds so we have our Mass we have our length we have our volume we have our time we can use any of those and convert every time you're going left you are moving the decimal point one spot to the left so for example if we have one gram let's say so we are starting at the base we're starting here and I want to know how many hectograms that is notice from my base I'm moving one two spots to the left so I would take my decimal point right here and move it two spots to the left so that would be01 hectograms if I'm starting at let's say CTI lers and let's say I have 254 Cen so find where centi is that's right here so here's where we're starting and let's say I want to go to let's go to kilers so I'm going over here to the pink I have to move the decimal point 1 2 3 4 five places to the left so again my decimal points here 1 2 3 4 five so that would be 0.254 kilers and the same thing would hold true that if you're moving to the right you would just move the decimal point to the right so if you we're going from let's say DEC to milligrams 1 two three four spots to the right now the only trick with this that you have to remember one you have to remember the order they go in so I highly recommend you think of an acronym to go along with these letters something that starts with a t a g an m a k an H that will help you the other big thing is that for a lot of them if the one right next to it you are just moving one decimal point the difference is if you're going from here to here that's actually moving it three decimal points so not just one you're moving three from here to here again is a jump of three and from here to here again is a jump of three that holds true on the right hand side as well that from Millie to micro is a jump of three micro to Nano and Nano to Pico are all jumps of three everything else whatever is right next to it is just a one jump so let's do an example let's say we have 7.89 millimet and I want to go to let's say nanometers so find out where Millie is Millie is right here to get to Nano I'm going over here so from Millie first I have to go to micro so that is three jumps so that's 1 two three and then I have to go to Nano which is another three so four five 5 six so I actually moving the decimal point six places to the right so that would be right here is my decimal point move it six places so one two one two 3 4 and that would be your answer so what is that 7, 890,000 nanometers are in 7.89 mm so that is how you work work with the metric system the only other thing I would say that would be weird or unfamiliar to you would maybe be micro so micro symbol it's a Greek letter and it looks like like a weird U or a weird M depending how you look at it and you can practice you know writing that but that is micro so write the conversion between microgram and Gram now depending how you look at this you could have two different answers I always like to take the bigger unit and give that a one so what do I mean by that so I have microgram and gr which one of those is bigger well if I look at my little timeline here anything to the left is bigger so I have gram right here and I have microgram right here so gram is bigger than microgram so what I would do is I would give the bigger unit of one and then I would do my whole decimal point movement and I know that I have to move it six places to the right to get to micro so that is 1 * 10 to 6 microgram now could you not put that in scientific notation and just say a million you could but you should get very comfortable using scientific notation now what if you gave the microgram the one what if you said 1 microG is equal to how many G well you would just go backward on your timeline you would be starting from here and you'd be going 1 2 3 four five six to the left so that would be 1 * 10 -6 G which is the same thing as that 001 GRS again get comfortable with scientific notation the same thing would hold true for micrometer and meter microc and second it's just a different base unit so that is the metric system if we go to the English system which we're familiar with here's just a couple things that you should have memorized so lengthwise 1 foot is equal to 12 in one yard is equal to 3 ft and 1 mile is 5,280 ft those three I would say are important to have memorized if you do not already Mass wise if you step on the scale it will tell you in pounds so what we should know is that one pound lb for pounds is equal to 16 oz volume units that you will see in the medical field are pints and cubic cenm so cubic centimeters or CCS you will also see cm to the third power very important that volume is just derived from length actually so you can see highlighted there 1 m is equal to 1 cubic cm so a cubic cimer is just a CM * a CM * a cenm and that is equal to 1 ml why would we use that comparison if we were doing volume displacement if we had an irregular-shaped object solid object we would have to put that in a graduated cylinder which I will show you shortly now how do we measure volume so on the right here you can see we have what's called a graduated cylinder you always want to read the bottom of the curve and that is called the meniscus and you will see this in lab always at the bottom so if I am reading this I can see this is my 80 line that's 81 82 and up appears 83 so the bottom of that falls below 83 and above 82 so it's 82 point and then you're making an educated guess on that next digit and this is where you get into significant figures it's called so I would say 82.5 and it looks like that's milliliters up there back to the English system units of volume which you might use in the kitchen if you like cooking one gallon is four quarts and one quart is equal to two pints my wife will often ask me questions when she's cooking like hey how many quarts are in a gallon or how many pints or cups are in this or that and I always tell her I speak I speak metric system I don't really know the English ones that great but these two you should know different glassware used to measure volume so you have a flask here you'll see this in the lab you have a graduated cylinder a grad cylinder and you have a syringe and you have a pipe pet graduated pipe pet it looks like okay so going back to what I was talking about before how one mill is 1 cubic cm if we have a normal shaped object like a rectangular prism like a box of some sort we can get the volume of that box by just doing length time width time height so if we have a box and we're measuring all the length width and height and let's say it's 20 by 20 by 20 we would do 20 * 20 * 20 and we' say it's 8,000 and let's say it's in centimeters we're saying we should really have these labeled centimet that would be 8,000 Cub cm and that's easy enough we have math formulas to help us with that but if we have IR regular-shaped objects we have to use something called volume displacement so you can see at the right there here is a graduated cylinder where our object is not in the water yet so what you would do is you'd fill that graduated cylinder to any volume that you wish you just put some water in it or whatever you're using wherever you want and then you would note what that is what is the volume that's called The V initial your initial volume and if we're looking at this picture it looks like it's a little bit above the 35 and below the 36 so let's say 35 5.5 m then you would put your object in the graduate cylinder and the water level would rise so if I'm looking at that it looks like it's right on the 39 level and that's called your final volume so I would say 39.0 again you always give one estimated guess there that's significant figures so to find the volume of the object you do the V final minus the V initial so in this case it would be the 39.0 minus the 35.5 and we would get 3.5 milliliters and that is the volume of that object there so 3.5 milliliters is the same thing as 3.5 cubic cm and again the reason we do this is because it is irregularly shaped this object there's no math formula that will tell you how to find the volume of that so that's volume displacement okay looking at these problems we are supposed to answer if it is English or metric system and then what is it measuring which base unit is it a length a mass or a volume so if you want to pause the video right now and do it yourself you can and I will give the answers right now so the first one is micrometer so that is metric and meter is a length six gallons gallons is an English unit and that is measuring volume kg is kilogram that is metric and that is a mass cubic centim that is metric and that is measuring a volume right that's the same thing as 8 milliliters 125 lb that is English and that is a mass and last one 0.6 milliliters that's metric and that is a volume and just recall that is the same thing as 0.6 cubic cenm what is the volume in milliliters of a cube measuring 2 cm aside so cube is a regularly shaped object and to find the volume of a cube we would do length time width time height so it's 2 cm or cube is equal right all the sides so this would be 2 cm * 2 cm * 2 cm and that would be 8 cubic cm and of course we know that a cubic cenm is equal to a milliliter so this is the same thing as 8 milliliters we just want to make sure we answered the question correctly there