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## 4th grade

### Course: 4th grade > Unit 14

Lesson 7: Converting units of length- Converting metric units of length
- Convert to smaller units (mm, cm, m, & km)
- Converting feet to inches
- Converting yards into inches
- Convert to smaller units (in, ft, yd, & mi)
- Metric units of length review (mm, cm, m, & km)
- US Customary units of length review (in, ft, yd, & mi)

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# Converting metric units of length

CCSS.Math:

Learn convert kilometers, meters, and centimeters. Created by Sal Khan.

## Want to join the conversation?

- how do you convert 75cm into meters

and millimeters there is no video for that(8 votes)- A meter is 100 centimeters, so 75 centimeters is 0.75 meters.

There are 10 millimeters in a centimeter, so 75 centimeters is 750 millimeters.(6 votes)

- a meter is 1000(3 votes)
- a meter has 1000 millimeters(8 votes)

- im so confused i need decimals(4 votes)
- It does not tell you about millimeters so how can you know what the answer is?(4 votes)
- Do people use hectameter in math?(4 votes)
- yeah sometimes (rarely)(1 vote)

- This video seems a little complicated don't you think?(4 votes)
- Yes, it seems complicted.(1 vote)

- how do you convert 12 L into mL? I don't know what mL means(3 votes)
- mL meas milliliter so 12 L= 12000 mL cause 1 L=1000 mL(2 votes)

- Convert 1 1/4km into metres(3 votes)
- what are centimeters meters decimeters decameters millimeters ?(2 votes)
- Units of length based on the meter. (The meter itself was originally defined as one ten-millionth of the distance from the equator to the North Pole, but has been redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86.)

The centi, deci and so on are what is called prefixes. This means that they specify how many times you should multiply by ten in relation to the base unit. 1 decimeter is 1/10 meters and 1 km is 1 * 1000

You can find a list what a specific prefix entails on this wikipedia page: https://en.wikipedia.org/wiki/Metric_prefix(3 votes)

- What does 4 meters equal in millimeter. Please someone answer my question.(2 votes)

## Video transcript

What I want to do
in this video is convert this amount
of kilometers into meters and centimeters. So we'll first start
with the 2 kilometers. And I encourage you to
now pause this video and try to do this on your own. Well, the one thing that we know
is that a kilometer literally means 1,000 meters. So you could literally view
this is as 2 times 1,000 meters. Let me write that down. So this is going to be equal
to 2 times 1,000 meters, which is equal to 2,000 meters. If we wanted to convert the
11 kilometers into meters, it's the same thing. 11 kilometers-- this right
over here-- means 1,000 meters. So you could think of it
as 11 times 1,000 meters. So 11 times 1,000 is
going to be 11,000 meters. Now let's convert these
distances into centimeters. And here we just
have to remember that 1 meter is equal
to 100 centimeters. Let me write that down. 1 meter is equal
to 100 centimeters. And that's because the prefix
centi means one hundredth. Another way you can write
it is that one centimeter is equal to one
hundredth of a meter. But here we have a
certain number of meters, and each of those
meters are going to be equivalent
to 100 centimeters. So if we wanted to write
2,000 meters as centimeters, we could say, well,
we have 2,000 meters. Each of those are going to be
equivalent to 100 centimeters. And so this is going to be
equal to 2,000 times 100. Well, that's going to
be 2, and since where we have the three
zeroes from the 2,000. And then every time
you multiply by 10, you're going to
add another zero. Or you're going to have
another zero at the end of it. And we're going to
be at multiplying by 100 is equivalent to
multiplying by 10 twice. So we're going to
have two more zeroes. So this is going to be
200,000 centimeters. Now let's do the same
thing right over here with the kilometers,
the 11 kilometers, which are 11,000 meters. And once again, I encourage
you to pause the video and try to convert
it into centimeters. Well, same idea. You have 11,000 meters,
and each of them are equivalent to
100 centimeters. So this is going to
be 11, and let's see, we have one, two, three,
four, five zeroes. So this gets us to
1,100,000 centimeters.