The Metric SystemThe Metric System

Seventh GradeSeventh Grade

What is the metric What is the metric system?system?

A common system of measurement used A common system of measurement used throughout most of the world throughout most of the world

A decimal system based on powers of 10A decimal system based on powers of 10 Scientists worldwide use the metric Scientists worldwide use the metric

system – it is precisesystem – it is precise AKA the International System of Units, AKA the International System of Units,

abbreviated SIabbreviated SI

What is the metric What is the metric system?system?

We use decimals to specify units of We use decimals to specify units of measurement when we need more measurement when we need more precision precision

For example, when specifying the height For example, when specifying the height of a person 1.63 meters tall, to say that of a person 1.63 meters tall, to say that person is 1 or 2 meters tall doesn’t give person is 1 or 2 meters tall doesn’t give us a very good idea how tall that person us a very good idea how tall that person really isreally is

Who invented it?Who invented it?

It was first proposed in 1791It was first proposed in 1791 The French were the first to adopt itThe French were the first to adopt it The National Assembly of France first The National Assembly of France first

declared the “new” measures to be the declared the “new” measures to be the legal measures in France in 1795legal measures in France in 1795

Its use in France was made mandatory in Its use in France was made mandatory in 18371837

Who uses it today?Who uses it today?

Most of the worldMost of the world All countries EXCEPT:All countries EXCEPT:

MyanmarMyanmar LiberiaLiberia The United StatesThe United States

All industrialized countries except the All industrialized countries except the U.S. uses the metric systemU.S. uses the metric system

The metric system is The metric system is based on powers of 10based on powers of 10

Why? Seems to be a logical choiceWhy? Seems to be a logical choice Many cultures have used 10 as the basis Many cultures have used 10 as the basis

for their number systemsfor their number systems Probably because humans have 10 Probably because humans have 10

fingers and 10 toesfingers and 10 toes

Basic Units Basic Units

LengthLength - the meter- the meter

Volume – the literVolume – the liter

Mass – the gramMass – the gram

Prefixes:Prefixes:

Metric units small than 1Metric units small than 1

have Latin Prefixes:have Latin Prefixes:

Deci = tenth = .1Deci = tenth = .1 Centi = hundredth = .01Centi = hundredth = .01 Milli = thousandth = .001Milli = thousandth = .001

Prefixes:Prefixes:

Metric units larger than 1 have Greek Metric units larger than 1 have Greek prefixes:prefixes:

Deka = ten = 10Deka = ten = 10 hecto = hundred = 100hecto = hundred = 100 Kilo = thousand = 1,000Kilo = thousand = 1,000

Focus on length:Focus on length:

Length = the distance between two fixed Length = the distance between two fixed points.points.

The standard unit of length in the metric The standard unit of length in the metric system is the meter.system is the meter.

A meter is a little longer than a yard.A meter is a little longer than a yard.

The meterThe meter Scientists spent years carefully Scientists spent years carefully

measuring two points on Earth at sea measuring two points on Earth at sea levellevel

They used these points to determine the They used these points to determine the distance from the north pole to the distance from the north pole to the equator – ¼ the circumference of the equator – ¼ the circumference of the EarthEarth

They then divided that distance into 10 They then divided that distance into 10 million parts – each part called a metermillion parts – each part called a meter

Other units of length:Other units of length:

Millimeter = mm = .001 meterMillimeter = mm = .001 meter Centimeter = cm = .01 meterCentimeter = cm = .01 meter Decimeter = dm = .1 meterDecimeter = dm = .1 meter Meter = m = 1 meterMeter = m = 1 meter Dekameter = dk = 10 metersDekameter = dk = 10 meters Hectometer = hm = 100 metersHectometer = hm = 100 meters Kilometer = km = 1,000 metersKilometer = km = 1,000 meters

Focus on massFocus on mass

Mass = the amount of matter in an objectMass = the amount of matter in an object

The standard unit of mass in the metric The standard unit of mass in the metric system is the kilogramsystem is the kilogram

A gram has about the same mass as a A gram has about the same mass as a paper clippaper clip

The gramThe gram

Scientists tried to establish a unit that Scientists tried to establish a unit that would describe how much an object would describe how much an object weighsweighs

Because water is readily available all Because water is readily available all over the world, they decided to call the over the world, they decided to call the weight of one cubic centimeter of pure weight of one cubic centimeter of pure water at a given temperature a gramwater at a given temperature a gram

The gramThe gram

However, weight is an intrinsically However, weight is an intrinsically unreliable measurementunreliable measurement

Weight is dependent on gravityWeight is dependent on gravity A more reliable measurement is that of A more reliable measurement is that of

mass – how much matter an object mass – how much matter an object containscontains

The kilogram became the standard unit The kilogram became the standard unit of mass around the worldof mass around the world

Other units of massOther units of mass

Milligram = mg = .001 gramMilligram = mg = .001 gram Centigram = cg = .01 gramCentigram = cg = .01 gram Decigram = dg = .1 gramDecigram = dg = .1 gram Gram = g = 1 gramGram = g = 1 gram Kilogram = kg = 1,000 gramsKilogram = kg = 1,000 grams

Focus on volumeFocus on volume

Volume = the amount of space an object Volume = the amount of space an object takes uptakes up

The standard unit of volume in the metric The standard unit of volume in the metric system is the litersystem is the liter

One liter is a little larger than a quartOne liter is a little larger than a quart

Other units of volume:Other units of volume:

Milliliter = ml = .001 literMilliliter = ml = .001 liter Centiliter = cl = .01 literCentiliter = cl = .01 liter Deciliter = dlDeciliter = dl = .1 liter= .1 liter Liter = L = 1 literLiter = L = 1 liter Kiloliter = kl = 1,000 litersKiloliter = kl = 1,000 liters

Focus on timeFocus on time

Time = interval or duration elapsing Time = interval or duration elapsing between eventsbetween events

The standard unit of time in the metric The standard unit of time in the metric system is the secondsystem is the second

Metric representation of second = sMetric representation of second = s

Other units of timeOther units of time

1 minute = 60 seconds1 minute = 60 seconds 1 hour = 60 minutes = 3,600 seconds1 hour = 60 minutes = 3,600 seconds 1 day = 24 hours1 day = 24 hours 1 week = 7 days1 week = 7 days 1 year = 365 ¼ days (amount of time it 1 year = 365 ¼ days (amount of time it

takes the Earth to travel around the sun)takes the Earth to travel around the sun)

Other units of timeOther units of time

In practice, every three calendar years In practice, every three calendar years will have 365 days, and every fourth year will have 365 days, and every fourth year is a “leap year”, which has 366 days, to is a “leap year”, which has 366 days, to make up for the extra quarter day over make up for the extra quarter day over four years. The years 2008, 2012, and four years. The years 2008, 2012, and 2016 will be leap years. This gives us a 2016 will be leap years. This gives us a total of 52 complete 7 day weeks in each total of 52 complete 7 day weeks in each calendar year, with 1 day left over (or two calendar year, with 1 day left over (or two in a leap year).in a leap year).

Other units of timeOther units of time

The year is divided into 12 months, each The year is divided into 12 months, each of which has 30 or 31 days, except for of which has 30 or 31 days, except for February, which has 28 days (or 29 days February, which has 28 days (or 29 days in a leap year)!in a leap year)!

Focus on temperatureFocus on temperature

Temperature = the measure of hotness or Temperature = the measure of hotness or coldnesscoldness

The standard unit of temperature in the The standard unit of temperature in the metric system is degrees Celsiusmetric system is degrees Celsius

Metric representation of temperature = Metric representation of temperature = °C°C

Focus on temperatureFocus on temperature

Temperature is expressed in degrees Temperature is expressed in degrees Celsius in the metric systemCelsius in the metric system

Water freezes at 0Water freezes at 0°C°C Water boils at 100°CWater boils at 100°C A hot day is about 30°CA hot day is about 30°C Normal body temperature is 37°CNormal body temperature is 37°C

Metric System vs. EnglishMetric System vs. English

1 meter = 1 yardstick plus the length of a 1 meter = 1 yardstick plus the length of a piece of chalkpiece of chalk

1 centimeter = the width of some part of 1 centimeter = the width of some part of your smallest finger or fingernailyour smallest finger or fingernail

1 kilometer = a little more than ½ a mile1 kilometer = a little more than ½ a mile 1 kilogram = about the mass of 2.2 lbs. of 1 kilogram = about the mass of 2.2 lbs. of

butterbutter

Metric System vs. EnglishMetric System vs. English

1 gram = about the mass of a large 1 gram = about the mass of a large thumbtack ( a nickel = about 5 grams)thumbtack ( a nickel = about 5 grams)

1 liter = 1 quart plus ¼ cup1 liter = 1 quart plus ¼ cup 1 milliliter = 1/5 tsp. (1 tsp. = 5 ml)1 milliliter = 1/5 tsp. (1 tsp. = 5 ml)

The end…The end…

Happy metricating!Happy metricating!