Metric Length
You can measure how long things are, or how tall, or how far apart they are. Those are are all examples of length measurements.

Example: This fork is 20 centimeters long
These are the most common measurements:
- Millimeters
- Centimeters
- Meters
- Kilometers
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Small units of length are called millimeters.
A millimeter is about the thickness of a plastic id card (or credit card).
Or about the thickness of 10 sheets of paper on top of each other.
This is a very small measurement!
When you have 10 millimeters, it can be called a centimeter.
1 centimeter = 10 millimeters
A fingernail is about one centimeter wide.
Two tape measures, one in mm, the other in cmYou might use millimeter or centimeters to measure how tall you are, or how wide a table is, but you would not use them to measure the length of football field. In order to do that, you can switch to meters.
A meter is equal to 100 centimeters.1 meter = 100 centimeters
The length of this guitar is about 1 meter
Meters might be used to measure the length of a house, or the size of a playground.
And because a centimeter is 10 millimeters:
1 meter = 1000 millimeters
A kilometer is equal to 1000 meters.When you need to get from one place to another, you measure the distance usingkilometers.
The distance from one city to another or how far a plane travels would be measured using kilometers.
Final thoughts about measuring length:
1 centimeter = 10 millimeters
1 meter = 100 centimeters
1 kilometer = 1000 meters
Lots of Examples
A centimeter (cm) is about:
- about as long as a staple
- the width of a highlighter
- the diameter of a belly button
- the width of 5 CD's stacked on top of each other
- the thickness of a notepad.
- the radius (half the diameter) of a US penny
A meter (m) is about:
- a little more than a yard (1 yard is exactly 0.9144 meters)
- the width of a doorway (most doorways are about 0.8 to 0.9 m)
- half the length of a bed
- the width of a large fridge
- the height of a countertop
- four rungs up a ladder
- five steps up a staircase
- the depth of the shallow end of a swimming pool
- the width of a dining table
- the height of a 5 year old
- shoulder to opposite wrist of an adult
- outstreched arms of a child
- waist high on an adult
 | One meter equals roughly one long step of an adult man.
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A kilometer (km) is about:
- a little over half a mile
- a quarter of the average depth of the ocean
- how far you walk in 12 minutes
 | | One kilometer equals ten minutes' walk.
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Length Questions