Measuring Metric Distance
The basic unit in the metric system for measuring distance is the meter. A meter is about the
distance from the floor to a doorknob. Distances that are longer or shorter than a meter can be described
using a metric prefix with the basic meter unit.
Shorter distances can be measured in centimeters. There are 100 centimeters in a meter. A single
centimeter is 1/100 of a meter. The width of your little finger or the width of a large paper clip is about a
centimeter. Very small lengths can be measured in millimeters. There are 1,000 millimeters in a meter. A
single millimeter is 1/1,000 of a meter. The wire on a paper clip is about a millimeter wide.
Longer distances can be measured in kilometers. A kilometer is the same length as 1,000 meters.
A meter is 1/1,000 of a kilometer. If you placed nine football fields end to end you would have a
kilometer.
Scientists often use abbreviations for metric units. It is important to know and recognize these
abbreviations. Notice that all of these abbreviations are lower case letters.
meter m
centimeter
cm
millimeter
mm
kilometer
km
To measure distance, we use a tool called meter stick. For shorter distances, a tool called a metric
ruler can be used. Below you see a sample of the scale you will see on both the meter stick and the
metric ruler. The length of an entire meter stick is one meter. It is divided into 100 parts called
centimeters. A centimeter = .0l meter. These are the longer marks on the meter stick. They are usually
numbered. The smallest marks on the meter stick are millimeters. There are 1,000 of these marks on each
meter stick. A millimeter = .001 meter. Each centimeter is equal to ten millimeters. You could also say
that a millimeter = .1 centimeter.
Notice that the line measures more than 5 but less than 6 centimeters. If you were to
measure this line to the nearest centimeter, you would say it is 6 cm long since it is closer to 6 cm
than 5 cm. This is not very precise, however. You might say that the line measures 5 cm, 7 mm
but this is not convenient to record and it is considered bad form to mix metric units. Since each
millimeter = .1 centimeter, you might say that the line is 5.7 cm long. You might also say that
the line is 57 mm long since there are 10 mm in each centimeter. Either way would be correct.
Measuring Metric Mass
Mass is the amount of matter in an object. In the metric system, mass is measured in units called
grams. How much is a gram? To get an idea, hold a nickel in your hand. The mass of a nickel is about 5
grams. A large paper clip has a mass of about 1 gram. One milliliter of water has a mass of one gram.
Masses larger or smaller than a gram can be described using prefixes with the basic gram unit.
The kilogram is the unit most used in measuring larger masses. One kilogram is the same as 1,000 grams
and is the mass of one liter of water. Masses that are smaller than a gram are measured in milligrams.
There are 1,000 milligrams in a single gram. To get an idea of how small one milligram is, pick up a
postage stamp. Its mass is about 20 milligrams.
Scientists often use abbreviations for metric units. It is important to know and recognize these
abbreviations. Notice that all of the abbreviations are lower case letters.
gram
g
kilogram
kg
milligram
mg
It is important to know that there is a difference between mass and weight. Mass refers to the
amount of matter an object has. Weight refers to the amount of force gravity exerts on an object. For most
practical purposes the two are interchangeable and are treated as if they are the same, but it is important to
keep in mind that there is a difference. The gram is the metric unit for measuring mass (not weight).
There are various types of laboratory balances. The beam balance that you use may look like one
the ones pictured below. They may be slightly different, but all beam balances have some common
features.
To find the mass of a substance you will need to follow a set of specific sets. First, be sure
the level indicator is at zero on the scale. Use the zero adjusting knob/screw if necessary to reset
the level indicator. Next, place all the rider masses at zero on their beam. Then place the
substances to be massed on the pan. You will then need to begin moving the largest rider mass one
notch at a time until the level indicator moves below the zero on the scale. When this happens,
move the largest rider mass backward one notch and leave it. Repeat that procedure for second
rider mass. Now move the smallest rider mass forward one number at a time until the level
indicator is at or below the zero on the scale. If the level indicator is at zero on the scale add the
values for all riders together. This is the mass of the substance. If the level indicator is below the
zero on the scale move it backward one line at a time until the level indicator is rests at zero then
add the values for the riders.
Measuring Metric Volume
Volume is the amount of space a substance takes up. In the metric system, the basic unit used to
measure liquid volume is the liter. Most students are familiar with liters because soda pop is packaged in
one, two, and three liter bottles.
Volumes smaller than a liter can be described using a metric prefix with the basic liter unit. Most
of the substances we measure in science class are measured in milliliters. There are 1,000 milliliters in a
liter. A single milliliter is 1/1,000 of a liter. A teaspoonful of liquid contains about 5 milliliters. A
Unifix© cube measures 1 centimeter by 1 centimeter by 1 centimeter. Solid volumes are measured in
cubic centimeters. If you were to fill the Unifix© cube with liquid, you would have one milliliter of
liquid.
Scientists often use abbreviations for metric units. It is important to know and recognize
these abbreviations. Notice that the abbreviation for liter is an upper case letter while the prefix is a lower
case letter.
liter L
milliliter
rnL
To measure liquid volume we use a beaker or a graduated cylinder. The marks on these
containers that indicate the number of milliliters are called graduations. When measuring a liquid in one
of these containers, you should view the liquid at eye level as shown in the diagram. If you are using a
graduated cylinder made of glass, you will notice that the upper surface of the liquid is curved or
crescent-shaped. This curved surface is called a meniscus. The liquid volume should be read from the
bottom of the meniscus. A plastic container will not have a meniscus. The volume is simply read from
the level of the liquid. The volume of the liquid in the diagram is 35 mL
It is important to determine how many milliliters are represented by each mark on the beaker or
graduated cylinder. If every single milliliter does not have a mark, you must estimate the amount if the
liquid level falls between two marks. Different containers are marked with different graduations. Look
carefully at the container you are using to determine the number of milliliters each graduation mark
represents
Volume by Displacement
Volume by displacement is the method used to find the volume of small or irregularly shaped
objects by noting the difference in the level of liquid before and after immersing an object into a
graduated cylinder or beaker of liquid. For a small object immersed in a graduated cylinder or beaker, the
volume displaced by the object can be read directly from the scale on the container.
To determine the volume of the irregular object, place an
amount of water in a graduated container, this is the initial volume.
Next, carefully place the irregular shaped object into the container
without splashing any of the water out of the container. Then read
the total volume in the container with the object and the initial
volume. Determine the objects volume by subtracting the initial
volume from the total volume. The difference is the volume of the
object.
Measuring Metric Temperature
Temperature is a measure of the amount of heat contained in an object or substance. In the
metric system, temperature is measured with a Celsius thermometer. Look at the Celsius
thermometer pictured below. Observe the three standard temperatures marked on the scale; the
temperature at which water boils (100 C), the temperature at which water freezes (0 C), and
normal body temperature (37 C).
The symbol  means degree. The unit for measuring temperature in the metric system is
degrees Celsius ( C). The temperature 20 C, for example, should be read twenty degrees Celsius.
A Celsius thermometer contains a liquid that rises and falls as the temperature changes. The temperature
is read by looking at the mark on the scale that corresponds to the level of the liquid. It is important to
determine the number of degrees represented by each mark so you can read the temperature accurately.