# Video: Kilometers

In this video, we will learn how to measure length in kilometers, convert kilometers to meters or mixed units, and compare lengths in kilometers and meters.

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### Video Transcript

Kilometers

In this video, we will learn how to measure length in kilometers, convert kilometers to meters or mixed units, and compare lengths in kilometers and meters.

When we’re traveling from one place to another, we can use kilometers to measure distance. These children are traveling to the beach. Let’s read the road sign to find out how many kilometers it is until they reach Sandy Beach. Did you notice the letters km? km is how we abbreviate kilometers. So it’s 15 kilometers to the beach. The children are going to stop at Blue Lagoon on their way to the beach. How many kilometers is it to the Blue Lagoon?

We can see from the road sign that next to Blue Lagoon it says the number three. And we know the unit of measurement is kilometers, so the children are three kilometers away from the Lagoon. A kilometer is equal to 1,000 meters. So if we wanted to write the distance to the Lagoon in meters, we would have to convert our kilometers into meters. And we can use this bar model to help. If one kilometer is equal to 1,000 meters, then three kilometers is equal to 3,000 meters. To convert kilometers to meters, we have to multiply the amount of kilometers by 1,000. Three kilometers multiplied by 1,000 is 3,000 meters.

When we multiply a number by 1,000, the digits move three places to the left. And if we want to convert an amount of meters to kilometers, we do the opposite. We divide the meters by 1,000. When we divide a number by 1,000, the digits move three places to the right. So if we want to convert the distance to the beach from kilometers to meters, we would need to multiply 15 by 1,000. When we multiply by 1,000, the digits move three places to the left. The distance to the beach is 15,000 meters.

We can also use kilometers to measure the length or height of objects. The height of this mountain is three kilometers 545 meters. Did you notice that this height has been given in mixed units, kilometers and meters? And the height of this mountain has been given in meters, 2,365 meters. If we were asked to compare the height of these two mountains, we’d need to convert them both to the same units of measurement. Let’s convert our three kilometers 545 meters into meters.

To do this, we can break the numbers apart, into kilometers and meters. We don’t need to convert this part because it’s already given in meters. We know that one kilometer is equal to 1,000 meters, so three kilometers is equal to 3,000 meters. Now, all we need to do is add our parts back together again. 3,000 plus 545 is 3,545 meters. Now that both of our heights are given in the same unit of measurement, we can compare them. Three kilometers 545 meters is greater than 2,365 meters. This is the tallest mountain.

The children have almost reached the beach. It’s only 500 meters until they get there. How many kilometers is it to the beach? We know that 1,000 meters equals one kilometer. We also know that 500 is half of 1,000. So 500 meters is equal to half a kilometer. A quarter of 1,000 is 250, so 250 meters is equal to a quarter of a kilometer. And 750 meters would be equal to three-quarters of a kilometer.

So far, we’ve learned that one kilometer is equal to 1,000 meters. We’ve learned that to convert from kilometers to meters, we multiply the amount of kilometers by 1,000. And to convert from meters to kilometers, we need to do the opposite, divide by 1,000. We’ve also learned that when we’re comparing distances or height or lengths, we need to compare the same units. If a measurement is given in mixed units, we may have to convert.

We’ve also learned that half a kilometer is equal to 500 meters, a quarter of a kilometer is equal to 250 meters, and three-quarters of a kilometer is equal to 750 meters. Let’s try some questions now to help us practice what we’ve learned about kilometers.

Which of the following is a true statement? 1,000 kilometers is equal to one meter. 100 kilometers is equal to one meter. 1,000 meters is equal to one kilometer. Or 100 meters is equal to one kilometer.

We know that one kilometer is equal to 1,000 meters. So we can say that this statement is a false statement. The units of measurement are the wrong way round. It should say 1,000 meters is equal to one kilometer. The second statement is also false. 100 kilometers is not equal to one meter. How about this statement? 1,000 meters is equal to one kilometer. This is true. We know that this statement is also false because there are 1,000 meters in one kilometer. The statement which is true is 1,000 meters is equal to one kilometer.

Complete: 6,521 meters is equal to what kilometers and what meters?

In this question, we’re given a measurement in meters, and we have to write it as an equivalent amount of kilometers and meters. Let’s use a part–whole model to help. The whole amount is 6,521 meters. And we have to write this as an amount in kilometers and meters. We know that one kilometer is equal to 1,000 meters. So if we partition 6,521 into 6,000 and 521, this will help us convert our 6,000 meters into kilometers. To convert an amount of meters to kilometers, we have to divide by 1,000. 6,000 divided by 1,000 equals six.

We converted our 6,000 meters into six kilometers. So the missing numbers are six and 521. 6,521 meters is equal to six kilometers and 521 meters. We’ve completed the equation. 6,521 meters is equal to six kilometers and 521 meters.

Complete: What meters is equal to three kilometers and 352 meters.

In this question, we’re given a measurement in mixed units, three kilometers and 352 meters. We have to write this as an amount in meters. And we’ve been given a part–whole model to help. We’re being asked to find the amount in meters. The amount we’ve been given has been partitioned or broken apart into an amount of kilometers, there are three, and an amount of meters, 352. 352 is already written in meters, so we just need to convert the amount in kilometers to an amount in meters.

If one kilometer is equal to 1,000 meters, how many meters are there in three kilometers? To convert from kilometers to meters, we have to multiply our amount of kilometers by 1,000. So one kilometer multiplied by 1,000 equals 1,000 meters. So to convert three kilometers to meters, we just need to multiply our three kilometers by 1,000. Three kilometers is equal to 3,000 meters.

Now all we need to do is add our two parts back together again, 3,000 meters plus 352 meters. The missing number is 3,352. 3,352 meters is equal to three kilometers and 352 meters.

Write in meters: five and a half kilometers.

In this question, we have to convert five and a half kilometers into meters. If one kilometer is equal to 1,000 meters, then five kilometers is equal to 5,000 meters. Now all we need to do is work out what half a kilometer is equal to in meters. What is half of 1,000? 5,000 plus 500 is 5,500 meters. Five and a half kilometers is equal to 5,500 meters.

Which is greater, 2,358 meters or three kilometers?

In this question, we’re being asked to compare two measurements, 2,358 meters and three kilometers. We’re being asked to compare two different units of measurement, meters and kilometers. When we’re comparing two measurements, it helps if we compare them using the same unit of measurement. We could convert our amount in kilometers into meters. If one kilometer equals 1,000 meters, we just need to multiply our kilometers by 1,000.

Three multiplied by 1,000 is 3,000. 2,358 is less than 3,000. Comparing two measurements with the same units is much easier. So if 2,358 meters is less than three kilometers, then three kilometers is greater than 2,358 meters. Three kilometers is greater.

So what have we learned in this video? We’ve learned that one kilometer is equal to 1,000 meters. We’ve also learned how to convert kilometers to meters and meters to kilometers. We learned that half a kilometer is equal to 500 meters and a quarter of a kilometer is equal to 250 meters. And finally, we learned that when we’re comparing lengths or distances, we need to compare the same units of measurement.