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## Basic geometry and measurement

### Course: Basic geometry and measurement > Unit 5

Lesson 4: Converting units of length# Metric units of length review (mm, cm, m, & km)

Review the size of millimeters, centimeters, meters, and kilometers and how to convert between them. Then, try some practice problems.

## Summary of metric units of distance

Kilometer | Meter | Centimeter | Millimeter |
---|---|---|---|

## What is distance?

Distance measures length. For example, the distance of a road is how long the road is.

In the metric system of measurement, the most common units of distance are millimeters, centimeters, meters, and kilometers.

### How big are metric units of distance?

A paper clip is about $1$

**millimeter**thick.A fingernail is about $1$

**centimeter**wide.The length of a guitar is about $1$

**meter**.A $1000$ meters. It is a little over half of a mile.

**kilometer**is equal to*Want to learn more about metric units of distance? Check out this video.*

## Converting larger units to smaller units

To convert larger units to smaller units we multiply the number of larger units by the green conversion factor for the appropriate smaller units.

**Example: Converting meters to centimeters:**

## Converting smaller units to larger units

To convert smaller units to larger units we divide the number of smaller units by the purple conversion factor for the appropriate larger units.

**Example: Converting meters to kilometers:**

*Want to learn more about converting between metric units of distance? Check out this video.*

## Practice set 2: Converting distance units

*Want to try more problems like this? Check out these exercises:*

Convert larger units to smaller units

Converting between units

## Want to join the conversation?

- What about micrometers?(37 votes)
- #1, I love the name, #2, A micrometer is 1000 times smaller than a centimeter.(38 votes)

- Is there anything before 'Millimeter' and after 'Kilometer' ?(16 votes)
- technically, as with any SI unit, yes there is.

practically: smaller than milli meter: yes. larger than kilo meter: no

this table shows all the possible prefixes: https://en.wikipedia.org/wiki/Metric_prefix

in physics, you occasionally come across nano meters, one nanometer = 10^-9 meters or 0.000000001 meters

going bigger, you could technically have a mega meter which would be 1000 kilometers, but i have never seen this in practice and most people would misunderstand you (in a metric country)(16 votes)

- Khan is not for nerds it is for people to study(21 votes)
- What is the difference between km and M?(9 votes)
- a km is a kilometer, and an M is a meter. There are 1,000 meters in a kilometer. In other words, one meter is 1/1,000 of a kilometer or 0.001 of a kilometer.(20 votes)

- How many millimeters are in 5 meters?(9 votes)
- I get messed up with km to mm.(3 votes)
- Converting from km to m requires multiplying by 1,000, because there are 1,000 m in one km.

Converting m to mm requires multiplying by 1,000, because there are 1,000 mm in one m.

It follows from these two facts that converting from km to mm requires multiplying by 1,000*1,000=1,000,000.

Have a blessed, wonderful day!(28 votes)

- Okay so if y'all don't get this, let me give you an example. So, 1 kilogram = 1,000 grams, right? So, if the question asks you how many grams are 4 kilograms, you multiply 4 by 1,000 which is 4,000. Because if 1 kilogram = 1,000 grams, 4 must be 4,000 grams.(15 votes)
- I have one tree that is 4 meters tall a second tree that is 3 m tall how many centimeters taller is the first tree(6 votes)
`100 cm is the answer`

(19 votes)

- Is there more measurements than just this?(13 votes)
- Yes- nanometers and micrometers are some smaller measurements(4 votes)

- Does anyone know how long 1 meter = ----- kilometer and how long 1 kilometer = -----meter(5 votes)
- The prefix 'kilo' means 1000, so there are 1000 meters for every kilometer and there are 0.001 kilometers for every meter.(13 votes)