The Metric SystemThe Metric System-why do we need to learn -why do we need to learn

this?this?Metric mishap caused loss of NASA orbiterOrbiterNASA's Climate Orbiter was lost September 23, 1999

By Robin LloydCNN Interactive Senior Writer

(CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.

We use the “English” systemWe use the “English” system

English systemEnglish system

Only in the USA and BritainOnly in the USA and Britain No systematic approachNo systematic approach

Based on body parts of the of royalty! And Based on body parts of the of royalty! And other Imperial connections…..other Imperial connections…..

Units Units Length = Inches Length = Inches (12 inches = length of King’s (12 inches = length of King’s

foot!!!)foot!!!)

Mass/Weight = Pounds Mass/Weight = Pounds Volume = Gallons Volume = Gallons (Queen Anne’s wine gallons!)(Queen Anne’s wine gallons!)

Metric or SI SystemMetric or SI System

Almost every country except USA and Almost every country except USA and BritainBritain Systematic approachSystematic approach

Based on 10’sBased on 10’s

UnitsUnits Length = MetersLength = Meters Mass/Weight = GramsMass/Weight = Grams Volume = LitersVolume = Liters Time = SecondsTime = Seconds Temperature = celsiusTemperature = celsius

Temperature scale of waterTemperature scale of water

English systemEnglish systemBoiling point Boiling point 212212°°FF

Freezing pointFreezing point3232°°FF

Metric SystemMetric SystemBoiling pointBoiling point 100100°°CC

Freezing pointFreezing point00°°CC

Fahrenheit Celsius

Temperature scale Temperature scale

English systemEnglish systemBody TempBody Temp 98.998.9°°FF

Metric SystemMetric SystemBody TempBody Temp 3737°°CC

Room temp: 25c

Some conversion relationships Some conversion relationships for GRAMSfor GRAMS::

1g = 1000 mg1g = 1000 mg can also be written as a can also be written as a fraction: fraction: 1000 mg1000 mg

1 g1 g

OR AS : OR AS : 1 g 1 g

1000m g1000m g

Example for Unit ConversionsExample for Unit Conversions 1Km = 1000m 1Km = 100000cm 1Km = 1000000mm 1Km = 1000000000 mm

1m = 100cm 1m = 1000mm 1m = 1000000 m

1cm = 10mm 1cm = 10000m 1mm = 1000m

Practice these conversionsPractice these conversions

Ex. 1: Convert 46.5 mg to grams.

46.5 mg

1 g1000 mg

= 0.0465g

Picket Fence Method for Metric Picket Fence Method for Metric Conversion ProblemsConversion Problems

What you start with goes here What you need to cancel out What you want to end with so you get what you want

Practice these conversionsPractice these conversions

Ex. 1: Convert 125cm to Km.

125 cm 1 m 100 cm

1Km1000m

0.00125Km

Kilo Kilo 1000X1000X

Hecto Hecto 100x100x

Deka Deka 10x10x

Std unitStd unit Deci Deci 1/101/10

Centi Centi 1/1001/100

Milli Milli 1/10001/1000

Kilometer Kilometer

1Km=1Km=

1000m1000m

(abbr. Km)(abbr. Km)

HectometHectometer 1Hm= er 1Hm= 100m100m

(abbr. (abbr. Hm)Hm)

DekameteDekameterr

1 1 Dm/dk)= Dm/dk)= 10m10m

(abbr. (abbr. Dm)Dm)

MetersMeters(Abbreviat(Abbreviation is m)ion is m)

DecimeterDecimeter

1dm=0.11dm=0.1mm

CentimeteCentimeterr

1cm1cm

0.01m0.01m

MillimeterMillimeter

1mm=1mm=

.001m.001m

Kilometer Kilometer

1KL=1KL=

1000L1000L

(abbr. KL)(abbr. KL)

HectometHectometer 1HL= er 1HL= 100L100L

(abbr. HL)(abbr. HL)

DekaliterDekaliter

1 DL= 10L1 DL= 10L

(abbr. (abbr. Dm)Dm)

LitersLiters

(L)(L)

DeciliterDeciliter

1dL=0.1L1dL=0.1L

CentiliterCentiliter

1cL1cL

0.01L0.01L

MillimeterMillimeter

1mL=1mL=

.001L.001L

GramGramss

(g)(g)

You fill this like the above row!

You fill this like the above row!

Homework Help!Homework Help!

11) 1 mL = 0.001L (see previous 11) 1 mL = 0.001L (see previous slide!)slide!)

12) 5 cm = 50 mm12) 5 cm = 50 mm 13) 10 mg = 0.01 g (1 mg = 0.001 g)13) 10 mg = 0.01 g (1 mg = 0.001 g) 14) 39 m = 39000 mm14) 39 m = 39000 mm You figure out the rest!You figure out the rest!