Category: Educational
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in this video i'm going to talk about a unit of length known as the meter which you might have heard of before it's really probably the most used unit of length in the world and so the natural question is how long
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is a meter well one way to get a rough sense of a meter is imagine a reasonably tall basketball player so a good taller a good bit taller than your average man so a good bit taller than me i'm about average height so that's your basketball player there
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he's got his basketball he might be roughly two meters tall so this would be two meters one meter and this lowercase m is short for meter and then two meters
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another way to think about a meter is if you took a long step if you're let's say seven or eight years old and if you were to take a long step you might travel about a meter so that's your long step
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right over right over there it might be close to a meter roughly it's not necessarily going to be exactly a meter but it might be close now a related unit of length is known as the centimeter
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and you might already recognize that it has the word has the word meter in it and it also has the word centi now you might already know the word cent ascent a hundred cents make a dollar you might know the word century that's a
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hundred years so you might say is this a hundred meters you'd be kinda close but kinda far off it's not a hundred meters it's not bigger than a meter it's actually a lot smaller than a meter a centimeter a hundred of them will equal
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one meter so one way to think about it is if i write it in shorthand 100 and you normally write it as lowercase c and m so 100 centimeters are equal to 1 meter so on these pictures right over here a centimeter would be
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much smaller than a meter right over there even that even what i just drew there would be a lot less than a centimeter and one way to think about a centimeter it might be if you stick your finger out your finger depending on how large your finger is
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might be about a centimeter wide as a grown average sized man my my finger is actually about two centimeters wide if i take my index finger and if i were to measure it i would approximate it as about two centimeters
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so a hundred centimeters make up a meter which hopefully makes a little bit of sense to you now given what we've just learned about meters and centimeters let's think about what is better to measure with depending on the size of the thing so if i was looking at a
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let's say a fairly tall tree of some kind what would i want to measure that with would i be more likely to measure that in meters or would i be more likely to measure that in centimeters pause this video and think about that
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well a fairly tall tree is going to be a lot taller than even this basketball player so normally people are likely to measure this in meters a reasonably tall tree could be 10 meters or 20 meters or even in certain cases 30 meters or taller
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now what if i were instead measuring the length of a mouse so my best drawing of a mouse here draws a little pause kind of looks like a fish with a tail but let's say that this is a mouse would i measure this in meters or centimeters
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well a mouse is much smaller in length than a tree is tall so you would likely measure this in centimeters a small mice my a small mouse i should say might be maybe 5
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5 or 10 centimeters in length right over here now let's compare another way or decide another way to think about whether we're measuring in centimeters or meters let's say that i went to the local
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the local gymnasium and there's a pool there there's a pool that's the water in the pool and i were to measure the length and i know it is 25 something it's either 25 meters or 25 centimeters
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remember this is the pool at the gym pause this video do you think this would be 25 centimeters or 25 meters well as you can imagine the length of a pool this tall basketball player many of them could lie down end to end to get to
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this length of this pool so this would be a 25 meter pool a 25 centimeter pool that would be maybe that actually would probably be about the size of a cell phone or maybe smaller or a little bit larger depending on the cell phone that you're talking
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about so for a pool you'd be talking in terms of meters what if we had a building of some kind so this is a building right over here and let's say it is a
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three-story or let's call it it's a four-story building and someone were to say that it is 15 something tall would this be 15 meters tall or 15 centimeters tall well 15 centimeters that might be a lego building a real building would be 15
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meters in this scenario now what if i were to say the length of my thumb the length of my thumb right over here and i know it is 5 something this length
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right over here it is five something it's either five meters or five centimeters which one do you think it is well if it was five meters i would be a very very very large giant my thumb would be twice as tall or more than
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twice as tall as a fairly tall basketball player so this would be five centimeters right over here so hopefully that gives you a sense of meters and centimeters and on khan academy there's a lot more practice so you can get a little bit more sense of estimating with these or thinking about when one set of
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one unit or the other is more appropriate