### Measuring Length - River Dell Regional School District

```Measuring
Length and Distance
in Metric Units
Some of the tools used to measure length
and distance are a metric ruler, a meter
stick and a metric tape measure.
Metric Units of Length Measurement
•
•
•
•
•
•
•
Meter (m) – Unit of measurement (starting point)
Millimeter (mm) – (1 thousandth of a meter, 0.001, 10-3)
Centimeter (cm) – (1 hundredth of a meter, 0.01, 10-2)
Decimeter (dm) – (1 tenth of a meter, 0.1, 10-1)
Decameter (dam) – (ten meters, 10, 101)
Hectometer (hm) – (1 hundred meters, 100, 102)
Kilometer (km) – (1 thousand meters, 1000, 103)
• The units decimeter, decameter and
hectometer are not used as often as the other
units.
• Meters or kilometers are used to measure
longer distances or longer things such as
school buses.
•For measuring longer distances, meter
sticks can be placed one after another
along the distance, counting the total
number.
•Smaller divisions of the meter
(millimeters and centimeters) are
used to measure the length of
shorter distances or things (like
pieces of chalk or height of a
school desk).
To put these measurements into perspective
we can compare them to everyday objects.
1 centimeter is about the width
of an average person’s thumbnail
thickness of a dime
This drawing shows 1/10th of a meter stick, a
decimeter (dm). It has 10 centimeters (cm) and
each of those centimeters has 10 millimeters
(mm).
The arrows indicate specific mm locations.
Length/Distance
• Kilometers (thousands of meters....Fort Worth to
Dallas TX, 50 km)
• Meters (a school bus, ~10 m)
• Centimeters (top of an average school desk, about 70
Cm)
• Millimeters (width of a dime, 1 mm)
Metric Conversions
• To convert larger units to smaller ones , you MULTIPLY by units of 10
• To convert smaller units to larger ones you DIVIDE by units of 10
– Example:
1000
kilometer
100
10
hectometer decameter
1
Units
(meters)
0.1
0.01
0.001
decimeter Centimeter millimeter
– To convert 2 meters to centimeters (1 hundredth of a meter), you multiply
by 100:
• 2 x 100 = 200 cm (2 meters = 200 centimeters)
– To convert 3 millimeters (1 thousandth of a meter) to meters, you divide by
1000
• 3 ÷ 1000 = 0.003 m (3 millimeters = 0.003 m)
OR
• Find out how far apart the two prefixes are on the line
above. For example, kilo and hecto are one place apart,
kilo and deka are two places apart, etc.
• Move the decimal point to the left to convert smaller
units or right to convert larger units by the number of
places you found in the previous step. If there is no
decimal in the number, assume it's after the last digit in
the number.
1000
kilometer
100
10
hectometer decameter
1
Units
(meters)
0.1
0.01
0.001
decimeter Centimeter millimeter
Example #1
• To convert 1 kilometer to meters (convert larger to
smaller), move the decimal 1 place to the RIGHT and
add zeros where needed for the number of places
you move down the table.
Decimal Point
Start
1
kilometer
0
0
hectometer decameter
End
0
meter
• 1 kilometer = 1000 meters
decimeter Centimeter millimeter
Example #2
• To convert 1 millimeter to meters (convert smaller to
larger), move the decimal 1 place to the LEFT and
add zeros where needed for the number of places
you move down the table.
Decimal Point
End
kilometer
hectometer decameter
meter
• 1 millimeter = 0.001 meters
0
0
Start
1
decimeter Centimeter millimeter
Convert the following measurements
• 2 meters to centimeters
200 cm
_________
• 4 kilometers to meters
4000 m
_________
• 7 meters to millimeters
7000 mm
_________
• 5 centimeters to meters
0.05 m
_________
• 3 decimeters to meters
0.3 m
_________
0.08 dm
• 8 millimeters to decimeters _________
We will now measure length/distance, first by
finding the correct millimeter and then stating the
answer in centimeters for “A” through “G”.
Stated as centimeters
We will start by measuring distance, first by finding
the correct millimeter and stating the answer in
centimeters for “A” through “G”. First, “A”.
Stated as centimeters
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. First, “A”.
Stated as centimeters
18 mm
1.8 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “B”.
Stated as centimeters
18 mm
1.8 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “B”.
Stated as centimeters
18 mm
32 mm
1.8 cm
3.2 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “C”.
Stated as centimeters
18 mm
32 mm
1.8 cm
3.2 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “C”.
Stated as centimeters
18 mm
32 mm
44 mm
1.8 cm
3.2 cm
4.4 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “D”.
Stated as centimeters
18 mm
32 mm
44 mm
1.8 cm
3.2 cm
4.4 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “D”.
Stated as centimeters
18
32
44
59
mm
mm
mm
mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “E”.
Stated as centimeters
18
32
44
59
mm
mm
mm
mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “E”.
Stated as centimeters
18 mm
32 mm
44 mm
59 mm
75 mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
7.5 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “F”.
Stated as centimeters
18 mm
32 mm
44 mm
59 mm
75 mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
7.5 cm
We will start by measuring distance, first by finding
the correct millimeter and then then stating the
answer in centimeters for “A” through “G”. Then,
“F”.
Stated as centimeters
18 mm
32 mm
44 mm
59 mm
75 mm
87 mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
7.5 cm
8.7 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “G”.
Stated as centimeters
18 mm
32 mm
44 mm
59 mm
75 mm
87 mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
7.5 cm
8.7 cm
We will start by measuring distance, first by finding
the correct millimeter and then stating the answer
in centimeters for “A” through “G”. Then, “G”.
Stated as centimeters
18 mm
32 mm
44 mm
59 mm
75 mm
87 mm
96 mm
1.8 cm
3.2 cm
4.4 cm
5.9 cm
7.5 cm
8.7 cm
9.6 cm
How long is Mr. Frog?
6.9 cm or 69 mm
How long is this fish in
millimeters? 60 mm
How many centimeters
is that? 6 cm
The butterflies wing
37
span is _________mm
or stated in
centimeters is
3.7
____________cm.
The caterpillar’s length in millimeters
21 mm or stated in centimeters
is _________
is ____________.
2.1 cm
Some rulers start at the very end of the stick and others
have a small space before the actual ruler starts.
The placement of one of these screwdrivers will give
you the wrong answer for the screwdriver’s length.
• Is this screwdriver 90 millimeters long (9 cm)?
OR
• Is it 94 millimeters long (9.4 cm)?
94 millimeters long (9.4 cm)
The edge of the screwdriver must be put at the “0” of the ruler
What is the length of this tooth pick?
In millimeters? Stated in centimeters?
65 mm
6.5 cm
What is the length of this paper clip in millimeters?
Stated in centimeters?
30 mm
3 cm
•Here is a little “pop” quiz as we finish
discussing the measurement of length.
•In pairs, measure your height with a
meter stick or metric measuring tape.
•How tall are you are in these metric
length units?
•
meters
•
centimeters
• millimeters
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