Metric Length
We can measure how long things are, or how tall, or how far apart they are. Those are all examples of
length measurements.
Example: This fork is 20 centimeters long
These are the most common measurements:
Millimeters
Centimeters
Meters
Kilometers
id card
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!
Fingers
When we 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 cm
We can use millimeters or centimeters to measure how tall we are, or how wide a table is, but to
measure the length of football field it is better to use meters.
1 meter A meter is equal to 100 centimeters.
1 meter = 100 centimeters
The length of this guitar is about 1 meter
Meters can 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
The back of this kitchen chair is 1 meter
Roads
A kilometer is equal to 1000 meters.
When we need to get from one place to another, we measure the distance using kilometers.
The distance from one city to another or how far a plane travels can 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
outstretched arms of a child
waist high on an adult
One meter equals roughly one long step of an adult man.
A kilometer (km) is about:
a little over half a mile
a quarter of the average depth of the ocean
One kilometer equals about 12 minutes' walk.