Learn about Unit conversion Video

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Learn about Unit conversion

Learn about Unit conversion Welcome to the presentation on Units. Let’s get started. So if were to ask you or if I were to say I have traveled .05 kilometers, how many centimeters have I traveled? It’s a question mark centimeters. So before we break it to the math, it’s important to just know what this prefix is centi and kilo mean. And it’s good to memorize this or when you first trying to do these problems you could just write it down in piece of paper to see you have a reference. So kilo- means a thousand, hecto-means a hundred, deca-means 10 you may recognize that from decade 10 years and then of course you have no prefix means 1, deci- is equal to .1 or 1/10, centi—I keep changing between cases—centi- is equal to .01or 1/100 and then mili is equal to .001 that’s the same thing as 1/1000. And the way I remember I mean centi- if you think if a centipede has a 100 feet, a millipede—I’m not sure if a millipede has a thousand feet but that’s the implication with someone has a millipede because pede means feet. So let’s go back to the problem. If I have .05 kilometers, how many centimeters do I have? So whenever I do a problem like this, I like to actually convert my number to meters because that’s very easy for me. And actually I’m going to abbreviate this as km and we can abbreviate this as cm for centimeters. So let’s say, .05 km—well, if I were to convert this into meters, is it going to be more than .05 meters or less than .05 meters? Well, a kilometer is a very large distance so in terms of meters it’s going to be a much bigger number. So we can multiply this times 1000 meters and I’ll do it over 1 for kilometer and what does that get? Well, .05 times a 1000 is equal to 5, right? I just multiplied .05 times a 1000 and with the units I now have kilometers times meters over kilometers and the kilometer is cancel out. And just your familiar with this, you can treat units exactly the same way that you treat numbers or variables. If you have the same unit and the numerator and the denominator you can cancel them out assuming that they’re not adding units, your multiplying units so your kilometers times meters divided by kilometers and that equals 50 meters. And it’s good to always do a reality check after every step. Usually when you just have a problem, if I want to go from kilometers to meters, I’m going to use that the number of thousand because that’s the relationship between a kilometer and a meter and you’re always confuse, do I multiply by thousand or divided by thousand. You know you will always say well, if I’m going to kilometers to meters, I’m going 1 kilometers is a 1000 meters, right? So I’m going to be multiplying by a 1000, I’m going to get a bigger number. So that’s why I went from .05 and I multiply that by a thousand and I get 50. So let’s get back to the problem. .05 kilometers is equal to 50 meters. We’re not done yet now you need to convert to 50 meters into centimeters. Well, we’ll we do the same thing. 50 meters times—how many—so what’s the relationship between meters and centimeters? Well, if you look at the chart, we see it’s a hundred. And the question I’m going to ask you, am I going to multiply by hundred or Am I going to divide by a hundred? What’s the same thing? We’re going from a bigger unit to a smaller unit so one of a bigger unit is equal to a bunch of the smaller unit so we’re going to multiply. So we say that is times a 100 centimeters per meter and that makes sense it’s a 100 centimeters per meter. So 50 meters times a 100 centimeter per meter is equal to 50 times a 100 is 5000 and then meters cancel out then you get centimeters. So we have here is the .05 kilometers is equal to 5000 centimeters. Let’s do another problem. I think the more examples you see it will make a little more sense. And always try to visualize what we’re doing the scale otherwise it’s very confusing whether you should multiply or divide. Let’s say I have 422 decigrams, grams are measure mass, it’s very—1 gram is actually a very small amount that can be measure I guess in the metric system they measure gold in terms of grams. And I want to convert this into milligrams. So before we start the problem let’s just do a reality check. Am I going from a bigger unit to a smaller unit or smaller unit to bigger unit? Well, decigrams that’s 1/10 of a gram and I’m going to 1000 of gram. So there are two ways of doing this, we can convert to grams and then convert to the other unit that sometimes make things easy or we could say well, how many milligrams is equal to 1 decigram. Well, a milligram as we see here is a 100 times smaller to go from 1/10 to 1/1000 you have to decrease in size by 100. So we could just say, 422 decigrams times 100 milligrams per decigram and then the decigram will cancel out and now I get was a 422 times a 100 that’s 42200 milligrams. Now, another way you could do this is the way we just did that last problem. We could say 422 decigrams, we could convert that to grams so we could say 422—I’m just going to say dg so that’s not a familiar unit the decigrams. And how many decigrams are there for gram? And if we’re going to gram we’re going to—let’s get 422 is going to be a smaller number of grams, right? so we could say, times 1 decigram is equal to how many grams. Well, 1 gram is equal to how many decigrams? Well, 1 gram is equal to 10 decigrams. And the reason why this makes sense is if we have a decigram in the4 numerator here, we want a decigram in the denominator here. So if we have decigrams cancel out. So 422 decigrams will equal—that divided by 10 is equal to 42.2 grams. And now, we could just go from grams to milligrams. Well, that’s an easy one. 1 gram is equal to a 100 milligrams so we could say, times 1000 milligram per gram, the grams cancel out and we’re left with 42200 milligrams, right? 42.2 times 1000. Hopefully that doesn’t confuse you too much. The important thing is to always take a step back and really visualize and think about—should I be getting a larger number or a smaller number than the one I start off with. I think you’re already there now, try some problems, have fun.

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Learn about Unit conversion

Welcome to the presentation on Units. Let’s get started.

So if were to ask you or if I were to say I have traveled .05 kilometers, how many centimeters have I traveled? It’s a question mark centimeters.

So before we break it to the math, it’s important to just know what this prefix is centi and kilo mean. And it’s good to memorize this or when you first trying to do these problems you could just write it down in piece of paper to see you have a reference. So kilo- means a thousand, hecto-means a hundred, deca-means 10 you may recognize that from decade 10 years and then of course you have no prefix means 1, deci- is equal to .1 or 1/10, centi—I keep changing between cases—centi- is equal to .01or 1/100 and then mili is equal to .001 that’s the same thing as 1/1000. And the way I remember I mean centi- if you think if a centipede has a 100 feet, a millipede—I’m not sure if a millipede has a thousand feet but that’s the implication with someone has a millipede because pede means feet.

So let’s go back to the problem. If I have .05 kilometers, how many centimeters do I have? So whenever I do a problem like this, I like to actually convert my number to meters because that’s very easy for me. And actually I’m going to abbreviate this as km and we can abbreviate this as cm for centimeters. So let’s say, .05 km—well, if I were to convert this into meters, is it going to be more than .05 meters or less than .05 meters? Well, a kilometer is a very large distance so in terms of meters it’s going to be a much bigger number. So we can multiply this times 1000 meters and I’ll do it over 1 for kilometer and what does that get? Well, .05 times a 1000 is equal to 5, right? I just multiplied .05 times a 1000 and with the units I now have kilometers times meters over kilometers and the kilometer is cancel out. And just your familiar with this, you can treat units exactly the same way that you treat numbers or variables. If you have the same unit and the numerator and the denominator you can cancel them out assuming that they’re not adding units, your multiplying units so your kilometers times meters divided by kilometers and that equals 50 meters.

And it’s good to always do a reality check after every step. Usually when you just have a problem, if I want to go from kilometers to meters, I’m going to use that the number of thousand because that’s the relationship between a kilometer and a meter and you’re always confuse, do I multiply by thousand or divided by thousand. You know you will always say well, if I’m going to kilometers to meters, I’m going 1 kilometers is a 1000 meters, right? So I’m going to be multiplying by a 1000, I’m going to get a bigger number. So that’s why I went from .05 and I multiply that by a thousand and I get 50. So let’s get back to the problem. .05 kilometers is equal to 50 meters. We’re not done yet now you need to convert to 50 meters into centimeters. Well, we’ll we do the same thing. 50 meters times—how many—so what’s the relationship between meters and centimeters? Well, if you look at the chart, we see it’s a hundred. And the question I’m going to ask you, am I going to multiply by hundred or Am I going to divide by a hundred? What’s the same thing? We’re going from a bigger unit to a smaller unit so one of a bigger unit is equal to a bunch of the smaller unit so we’re going to multiply. So we say that is times a 100 centimeters per meter and that makes sense it’s a 100 centimeters per meter. So 50 meters times a 100 centimeter per meter is equal to 50 times a 100 is 5000 and then meters cancel out then you get centimeters. So we have here is the .05 kilometers is equal to 5000 centimeters.

Let’s do another problem. I think the more examples you see it will make a little more sense. And always try to visualize what we’re doing the scale otherwise it’s very confusing whether you should multiply or divide. Let’s say I have 422 decigrams, grams are measure mass, it’s very—1 gram is actually a very small amount that can be measure I guess in the metric system they measure gold in terms of grams. And I want to convert this into milligrams. So before we start the problem let’s just do a reality check. Am I going from a bigger unit to a smaller unit or smaller unit to bigger unit? Well, decigrams that’s 1/10 of a gram and I’m going to 1000 of gram. So there are two ways of doing this, we can convert to grams and then convert to the other unit that sometimes make things easy or we could say well, how many milligrams is equal to 1 decigram. Well, a milligram as we see here is a 100 times smaller to go from 1/10 to 1/1000 you have to decrease in size by 100. So we could just say, 422 decigrams times 100 milligrams per decigram and then the decigram will cancel out and now I get was a 422 times a 100 that’s 42200 milligrams.

Now, another way you could do this is the way we just did that last problem. We could say 422 decigrams, we could convert that to grams so we could say 422—I’m just going to say dg so that’s not a familiar unit the decigrams. And how many decigrams are there for gram? And if we’re going to gram we’re going to—let’s get 422 is going to be a smaller number of grams, right? so we could say, times 1 decigram is equal to how many grams. Well, 1 gram is equal to how many decigrams? Well, 1 gram is equal to 10 decigrams. And the reason why this makes sense is if we have a decigram in the4 numerator here, we want a decigram in the denominator here. So if we have decigrams cancel out. So 422 decigrams will equal—that divided by 10 is equal to 42.2 grams. And now, we could just go from grams to milligrams. Well, that’s an easy one. 1 gram is equal to a 100 milligrams so we could say, times 1000 milligram per gram, the grams cancel out and we’re left with 42200 milligrams, right? 42.2 times 1000. Hopefully that doesn’t confuse you too much. The important thing is to always take a step back and really visualize and think about—should I be getting a larger number or a smaller number than the one I start off with. I think you’re already there now, try some problems, have fun.

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