Metric Conversions

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Transcript Metric Conversions

METRIC CONVERSIONS
THE METRIC SYSTEM

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Scientists use the metric system of measurement.
The metric system is different from the system of
measurement used in the U.S.
The metric system can be easier to use because it is
based on powers of ten.
BASE UNITS
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Each quantity is measured by a base unit.
Base units are the standard units used to
measure each quantity.
The most common base units are:
Length – meter
 Mass – gram
 Volume – liter
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METRIC PREFIXES
 Prefixes
are added to the base units to show
very large or very small quantities.
Prefix
Milli
Centi
Deci
Base Unit
Deka
Hecto
Kilo
Meaning
One thousandth
One hundredth
One Tenth
------Ten
One Hundred
One Thousand
Numerical Value
.001
.01
.1
1.0
10.0
100.0
1,000.0
METRIC PREFIXES

Prefixes help condense numbers to make them
more manageable.
Example:
The distance of a charity race is measured as
5000 meters.
This same quantity can be expressed as 5
kilometers.
METRIC CONVERSIONS
 Measurements
can be converted or changed
from one unit to another.
 Only
measurements that use the same base
unit can be converted (centimeters to
millimeters, or kilograms to grams).
 Cannot
convert measurements with different
base units because they measure different
things
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grams measure mass, meters measure length, etc.
CONVERSION FACTORS
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When converting from one unit to another, multiply
the number given in the problem by the conversion
factor.
Conversion factors show how many of the smaller
units are in the larger unit.
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Example: There are 100cm in 1m
The smaller unit gets the bigger number and the
larger unit gets a 1.
 The number in front of the small unit depends on
which prefix is being used.
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Centi- means one hundredth, so a centimeter is 1/100 of a
meter
Example: 100cm
or
1m
1m
100cm
SETTING UP CONVERSIONS
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Rules for setting up conversion factors:
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1. The unit given in the problem goes on the bottom of the
fraction.
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2. The unit you are trying to find goes on the top.
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3. The larger unit will always get a 1.
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4. The smaller unit gets the larger number, depending on
the prefix being used.
CONVERSIONS – LARGE TO SMALL
UNITS
Example Problem:
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How do you convert 1.85m into centimeters?
Meters are given in the problem (goes on bottom). We are
trying to find centimeters (goes on top).
 Meters are bigger than centimeters, so meters gets a 1.
 There are 100cm in a meter, so the conversion factor is
100cm
1m
1.85m x 100cm = 185cm
1m
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CONVERSIONS - SMALL TO LARGE
UNITS
Example Problem:
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How do you convert 185cm into meters?
Centimeters are given in the problem (goes on bottom).
We are trying to find meters (goes on top).
 Meters are larger than centimeters, so meters gets a 1.
 There are 100cm in a meter, so the conversion factor
is:
1m
100cm

185cm x 1m
100cm
=
1.85m
PRACTICE PROBLEMS – LARGE TO
SMALL UNITS
1.
Convert 1.6 kilograms (kg) to grams (g)
2. Convert 3.65 liters (L) to milliliters (mL)
3. Convert 2.75 meters (m) to centimeters (cm)
PRACTICE PROBLEMS – LARGE TO
SMALL UNITS (ANSWERS)
1.
1.6kg x 1000g = 1600g
1kg
2. 3.65L x 1000mL = 3650mL
1L
3. 2.75m x 100cm x = 275cm
1m
PRACTICE PROBLEMS – SMALL TO
LARGE UNITS
1. Convert 550 millimeters (mm) to meters (m)
2. Convert 45 decigrams (dg) to grams (g)
3. Convert 90 liters (l) to dekaliters (dal)
PRACTICE PROBLEMS – SMALL TO
LARGE UNITS (ANSWERS)
1.
550mL x 1L = 0.550L
1000mL
2. 45dg x 1g = 4.5g
10dg
3. 90L x 1dal = 9dal
10L