MetricSystem

Part 1

The Metric System

• Is a system of measurement.

• Is also known as the “S.I. System”.

(System International)

Metric System

s second Time

o C degrees celsiusTemperature

Lliter Volume

g gram Mass

m meterDistance

Unit Symbol UnitQuantity

Prefixes

ExampleMeans..SymbolPrefix

cghundredthc centi-

kmthousandkkilo-

mLthousandthmmilli-

every student should know…

Tools of Measurement

graduated cylinder or

beaker

liter

(L)

Volume

balancegram

(g)

Mass

meterstick or ruler

meter

(m)

Distance

ToolUnit

(unit symbol)

Quantity

WHY USE METRIC?

Benefits of the Metric System:

• It uses the decimal system (10’s!)

• It is an International Standard.

• The units relate to each other.*

*(More on this later!)

kilo, centi, milli• Be able to give your

answer using any of these prefixes!

For example:• A snowboard is

– 1.85 m

or– 185 cm

or– 1850 mm

How do you do that?

Common Sense:

1. The Metric System prefixes work by multiples of 10.

So, the answer must be found by just moving the decimal point. Some possible answers are:

15cm, 150 cm, 1500 cm,

0.15 cm, 0.015 cm

2. Which of these are reasonable answers?

Problem:How many centimeters is 1.5 meters?

There are many ways to solve this problem. One way is

Does the measurement make sense?– 1cm = width of a fingernail

– 1 g = mass of a push pin

– 1 mL = ~20 drops of water

Practice Guessing:

1.5 m =

12 cm =

0.295 m =

0.8 m =

150

0.12

295

80

cm

m

mm

cm

MetricSystem

Part 2

Metric System

Lliter Volume

g gram Mass

m meterDistance

Unit Symbol UnitQuantity

kilo, centi, milli• Be able to give your

answer using any of these prefixes!

For example:• A snowboard is

– 1.85 m

or– 185 cm

or– 1850 mm

How do you do that?

Practice Guessing:

1.5 m =

12 cm =

0.295 m =

0.8 m =

150

0.12

295

80

cm

m

mm

cm

Metric Staircase.

• Move up a step (left):…decimal moves left

• Move down a step (right):…Decimal moves right

centi

base

kilo

millic - centi

base

k - kilo

m - milli

d - deci

da - deca

h - hecto

(no prefix) -just meter, liter, or gram

Practice

1500 cm =

0.012 m =

29,500 cm =

0.08 km =

15

12

0.295

8000

m

mm

km

cm

Does the measurement make sense?– 1cm = width of a fingernail

– 1 g = mass of a push pin

– 1 mL = ~20 drops of water

Metric System

Lliter Volume

g gram Mass

m meterDistance

Unit Symbol UnitQuantity

What is mass?

• Mass is a measure of the amount of a substance.

•Mass is not weight

•Mass is not “how much space something takes up”; (that’s what volume is!)

Mass versus Weight

• Your mass is the same everywhere in the universe

•Your weight is less on the moon than it is on earth, because weight depends on gravity. link

Tools of Measurement

graduated cylinder or

beaker

liter

(L)

Volume

balancegram

(g)

Mass

meterstick or ruler

meter

(m)

Distance

ToolUnit

(unit symbol)

Quantity

Practice Prefixes, Methods of Metric Conversion

• Prefixes are Universal– cg,cm,cL, etc.

• Review Methods:– Common sense

– Metric Staircase

• Introduce Method:– Dimensional Analysis

• Practice with balances• Practice with common

sense conversion and then staircase conversion using grams and kilograms, etc.