Metric System
(SI Units)
“I’m ten times better than the Standard
system of measurement!”
Metric System
The metric system is based on a base unit
that corresponds to a certain type of
measurement.
BASE UNIT
MEASURES
Meter
Length
Liter
Volume
Gram
Mass
Metric System
Prefixes plus base units make up the metric
system!
PREFIX
…PLUS BASE UNIT
Kilo -
Kilo+gram = Kilogram
Hecto -
Hecto+liter = hectoliter
Deka -
Deka+gram = dekagram
Deci -
Deci+liter = deciliter
Centi -
Centi+meter = centimeter
Milli -
Milli+meter = milliliter
Metric System
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
Centi-
Milli-
Metric System
The three prefixes that we will use the
most are:
– Kilo = i.e. - kilometer, kilogram
– Centi = i.e. - centimeter, centigram
– Milli = i.e. - milliliter, milligram
Metric System
So, if you needed to measure length you
would choose ? as your base unit
meter
– Length of a tree branch
• 1.5 meters
– Length of a room
• 5 meters
– Length of a ball of twine stretched out
• 25 meters
Metric System
But what if you need to measure a longer
distance, like from your house to school?
– Let’s say you live approximately 1 mile
from school
• 1 mile = 1609 meters
– 1609 is a big number, but what if you add a
prefix to the base unit, you make it easier
to manage:
• 1609 meters = 1.609 kilometers
Metric System
The prefixes are based on powers of 10.
What does this mean?
From each prefix every “step” in the chart is either:
• 10 times larger (to the right) than the base unit
or
• 10 times smaller (to the left) than the base unit
Kilo-
Hecto-
.001
.01
Deka-
.10
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
Because all of the unit relationships in the metric
system are based on multiples of ten, it is easy to
convert between units; just multiply or divide by 10!
For example:
• Centimeters are 10 times larger than millimeters
So..
• 1 centimeter = 10 millimeters
Kilo-
Hecto-
.001
.01
Deka-
.10
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
1 centimeter = 10 millimeters
40
1 mm
41
1 mm
1 mm
1 mm
1 mm
1 mm
40
1 mm
1 mm
1 mm
1 mm
41
1 cm
Metric System
For example, let’s go from a base unit to centi• For each “step” to right, you are multiplying by 10.
1 liter(base) = 10 deciliters = 100 centiliters
( 1 x 10 = 10)
Kilo-
Hecto-
Deka-
=
(10 x 10 = 100)
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Lets Try:
2 grams = 20 decigrams = 200 centigrams
(2 x 10 = 20)
Kilo-
Hecto-
Deka-
=
(20 x 10 = 200)
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Another way to move within the metric
system is by moving the decimal point one
place for each “step” desired.
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Example: change meters to millimeters
1.0 meter =
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Example: change meters to millimeters
1.0 m = 10.0 decimeters
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Example: change meters to millimeters
1.0 m = 10.0 dm
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Example: change meters to millimeters
1.0 m = 10.0 dm = 100 centimeters
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Example: change meters to millimeters
1.0 m = 10.0 dm = 100.0 centimeters
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
Example: change meters to millimeters
1.0 m = 10.0 dm = 100.0 cm = 1000 millimeters
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
Metric System
So for every “step” from the base unit to
milli, we moved the decimal
1 place to the right.
Kilo-
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
Now let’s try converting meters to kilometers.
We’ll use our previous example: the distance
traveled from your house to school…..
1609 meters = ? kilometers
Kilo-
.001
Hecto-
Deka-
.01
.1
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
1609 meters = ? Kilometers
For every “step” from the base unit to kilo, we
moved the decimal 1 place to the left.
Kilo-
.001
Hecto-
Deka-
.01
.1
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
1609 meters = ? Kilometers
For every “step” from the base unit to kilo, we
moved the decimal 1 place to the left.
1609.
Kilo-
.001
Hecto-
Deka-
.01
.1
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
1609 meters = ? Kilometers
For every “step” from the base unit to kilo, we
moved the decimal 1 place to the left.
Kilo-
.001
160.9
1609.
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
.01
.1
1
10
Centi-
100
Milli-
1000
Metric System
1609 meters = ? Kilometers
For every “step” from the base unit to kilo, we
moved the decimal 1 place to the left.
16.09
Kilo-
.001
160.9
1609.
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
.01
.1
1
10
Centi-
100
Milli-
1000
Metric System
1609 meters = ? Kilometers
For every “step” from the base unit to kilo, we
moved the decimal 1 place to the left.
1.609
Kilo-
.001
16.09
160.9
1609.
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
.01
.1
1
10
Centi-
100
Milli-
1000
Metric System
1609 meters = 1.609 Kilometers
For every “step” from the base unit to kilo, we
moved the decimal 1 place to the left.
1.609
Kilo-
.001
16.09
160.9
1609.
Hecto-
Deka-
BASE UNIT
Meter
DeciGram
liter
.01
.1
1
10
Centi-
100
Milli-
1000
Metric System
If you move to the left (in the “steps” chart),
move the decimal to the left
If you move to the right (in the “steps” chart),
move the decimal to the right
Kilo-
.001
Hecto-
Deka-
.01
.1
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
Now, let’s start from centimeters and convert to
kilometers
400000 centimeters = ?
400000. centimeters = 4.00000 kilometers
Kilo-
.001
Hecto-
Deka-
.01
.1
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000
Metric System
Summary
– Base units in the metric system are meter, liter, gram
– Metric system is based on powers of 10
– For conversions within the metric system, each “step” is 1
decimal place to the right or left
– Using the conversion chart below, converting to the
right, moves the decimal to the right and vice versa.
Kilo-
.001
Hecto-
Deka-
.01
.1
BASE UNIT
Meter
DeciGram
liter
1
10
Centi-
100
Milli-
1000