MEASURING IN METRICS: LENGTH
Introduction
The metric system is a system of measurement based on multiples of
ten. The metric system uses these units: meter for length, gram for
mass and liter for volume. The system was developed in the 1700s
by the French Academy of Sciences in order to have one universal
measuring standard called the International System of Units. The
units are often referred to as SI units for this reason. Because the
metric system is based on tens, it is fairly easy to use, especially for
making calculations. Scientists all over the world use this system of
measurement. This allows scientists from any country to duplicate an
experiment using correct measurements. In this activity, you will
practice measuring length in SI units. The Data Table below provides
information on the meter.
Data Table 1
Name
Abbreviation
Measurement
millimeter
mm
1/1,000 of a meter
centimeter
cm
1/100 of a meter
decimeter
dm
1/10 of a meter
meter
m
basic unit for measuring length
dekameter
dkm
10 meters
hectometer
hm
100 meters
kilometer
km
1,000 meters
On a metric ruler or meterstick, the distance between two of the
small lines is a millimeter (mm). The distance between the numbers
© Infobase Publishing
MEASURING IN METRICS: LENGTH
2
is a centimeter (cm). 100 cm is equivalent to 1 meter. Figure 1
shows an enlarged version of a metric ruler.
1 cm
1 mm
CM
1
2
3
4
Figure 1
Time Needed
30 minutes
What You Need
✎
✎
✎
✎
✎
✎
✎
✎
ring stand
unsharpened pencil
10 pennies
shoe
circle
ruler with metric measurements
pencil
lined paper
Safety Precautions
Please review and follow the safety guidelines.
© Infobase Publishing
MEASURING IN METRICS: LENGTH
3
What You Do
1. Using the ruler, measure the height of the base of the ring stand
to the nearest mm (see Figure 2). Record your measurement.
ring stand
height of base
Figure 2
2. Using the ruler, measure the width of the base of the ring stand
to the nearest mm (see Figure 3). Record your measurement.
ring stand
width of base
Figure 3
© Infobase Publishing
MEASURING IN METRICS: LENGTH
4
3. Measure the radius of the circle to the nearest cm
(see Figure 4). Record your measurement.
r
radius
Figure 4
4. Measure the diameter of the circle to the nearest cm (see
Figure 5). Record your measurement.
diameter
Figure 5
5. Measure the length of an unsharpened pencil (including eraser)
in cm. Record your measurement.
6. Measure the length of your shoe to the nearest cm. Record your
measurement.
7. Stack 10 pennies (Figure 6)
D
GO
W E
TR
U
T
IN
S
LIBERTY
2007
height of
pennies
Figure 6
© Infobase Publishing
MEASURING IN METRICS: LENGTH
8. Measure how tall (the height) the stack of 10 pennies is in cm.
Record your measurement.
Observations
1. What is another name for 1,000 meters?
2. Draw a line 15 cm long below this sentence.
a. How many mm is this line equal to?
b. How many m is this line equal to?
c. How many kilometers (km) is this line equal to?
3. Based on your measurement of 10 pennies, how tall would a
stack of 100 pennies be in cm?
4. Using your shoe length measurement, determine how many
shoes would it take (heel to toe) to make 1 meter (m).
© Infobase Publishing
5
SAFETY PRECAUTIONS
Review Before Starting Any Experiment
GENERAL
obtain your teacher’s permission for experiments
• Always
performed at school, and obtain your parent’s permission for
experiments performed at home, before attempting any
experiment.
all instructions for an experiment several times before
• Read
starting the experiment, and follow the directions exactly.
an experiment requires adult supervision, do not perform the
• Ifexperiment
unless you have an adult supervising you the entire
time you are performing the experiment.
your hands before the start of and after each experiment
• Wash
you perform.
• Keep your work area clean.
eat or drink while performing a lab experiment. Never taste
• Never
a substance used in an experiment unless you are told that it is
safe to do so.
aware of the location of safety equipment you may need in an
• Be
emergency, such as running water, an eyewash if you are at
school, and a fire extinguisher.
you are going outside, make sure you have permission to go
• Iffrom
your teacher and parent. Take a buddy with you, and dress
appropriately for the weather. Make sure you or someone who
accompanies you is familiar with the area, and bring along a
first-aid kit in case of an emergency.
• Never look directly into the Sun.
CHEMICAL SAFETY
wear goggles when working with chemicals, such as acids
• Always
and bases, and near heat sources like flames. If at all possible,
avoid wearing contact lenses when working with chemicals.
© Infobase Publishing
SAFETY PRECAUTIONS
2
any substance gets into your eyes, notify an adult (e.g., your
• Ifteacher
or parent) immediately, and flush your eyes with running
water for at least 15 or more minutes. Do not mix chemicals
unless you are told to do so by a teacher or parent.
• Never touch, taste, or smell chemicals unless instructed to do so.
• Keep chemicals in closed containers when they are not in use.
of all used chemicals properly. Do not pour any
• Dispose
chemicals or solids down the drain unless instructed to do so.
safety gloves and a plastic apron when handling chemicals.
• Use
If any chemicals spill on your skin, rinse the affected area with
running water for at least 10 minutes, and notify your teacher or
parent immediately.
precautions to avoid spilling chemicals. If a chemical spills
• Take
on any surface, notify your teacher or parent immediately to
assist with clean-up.
caution when using sharp instruments such as knives or
• Exercise
scissors. Always cut away from yourself, not toward yourself. If
you cut yourself, notify your teacher or parent immediately.
GLASSWARE
• Clean glassware when you are finished with the experiment.
careful when using glassware. If a piece of glassware breaks,
• Be
have an adult assist you in clean-up to avoid injuries from broken
glass. Never use broken or damaged glassware.
FIRE SAFETY
not heat glassware that is not completely dry. Do not pick up
• Do
hot glassware without heat-resistant gloves or tongs.
heating glassware, keep it away from yourself and from
• When
others.
not heat anything unless instructed to do so by a teacher
• Do
or parent.
© Infobase Publishing
SAFETY PRECAUTIONS
3
• Do not heat substances in a closed container.
an experiment, make sure that all heating sources are off
• After
and that all flames have been put out.
• Do not reach across such heating sources as flames.
you have long hair, tie it back, out of the way. Do not wear
• Ifclothing
with loose sleeves, scarves, bows, ties, or anything else
that may hang into a fire. Do not wear long earrings.
ELECTRICAL SAFETY
• Do not touch electrical equipment when your hands are wet.
not plug many electrical devices into one outlet or use an
• Do
extension cord.
© Infobase Publishing