310110

210

310

610

910

Metric System• The metric system is based on a base

unit that corresponds to a certain kind of measurement

• Length = meter• Volume = liter• Weight (Mass) = gram

• Prefixes plus base units make up the metric system – Example:

• Centi + meter = Centimeter• Kilo + liter = Kiloliter

Metric System• These prefixes are based on powers of

10. What does this mean?– From each prefix every “step” is either:

• 10 times larger or

• 10 times smaller

– For example• Centimeters are 10 times larger than millimeters• 1 centimeter = 10 millimeters

kilo hecto deca

Base Units

metergramliter

deci centi milli

Metric System• For each “step” to right,

you are multiplying by 10

• For example, let’s go from a base unit to centi

1 liter = 10 deciliters = 100 centiliters

2 grams = 20 decigrams = 200 centigrams

kilo hecto deca

meterliter

gram

deci centi milli

( 1 x 10 = 10) = (10 x 10 = 100)

(2 x 10 = 20) = (20 x 10 = 200)

Metric System• An easy way to move within the metric

system is by moving the decimal point one place for each “step” desired

Example: change meters to centimeters

1 meter = 10 decimeters = 100 centimetersor

1.00 meter = 10.0 decimeters = 100. centimeters

kilo hecto deca

meterliter

gram

deci centi milli

Metric System• Now let’s try our previous example from

meters to kilometers:16093 meters = 1609.3 decameters =

160.93 hectometers = 16.093 kilometers

• So for every “step” from the base unit to kilo, we moved the decimal 1 place to the left (the same direction as in the diagram below)

kilo hecto deca

meterliter

gram

deci centi milli

Metric System• If you move to the left in the diagram,

move the decimal to the left

• If you move to the right in the diagram, move the decimal to the right

kilo hecto deca

meterliter

gram

deci centi milli

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 diagram below, converting to the right,

moves the decimal to the right and vice versa

kilo hecto deca

meterliter

gram

deci centi milli

Measuring Distance (Length):

• Length is the distance between two points.

• SI base unit for length is m• We need to use different unites

sometimes:– cm for things like a pencil– Km for long distances like between RAK and

Dubai.– 1m = 100 cm

– 1Km = 1000 m– 1cm = 10 mm– 1dm = 10 cm

Measuring Volume

• Volume: the amount of space occupied by an object.

• You’ll learn how to measure the volume of:

1.Regular solids, like a cube. 2.Liquids.3.Irregular solids, like a pencil or a

crown

1. Volume of regular solids:

Ex: a cube

V = l x w x h = 5 cm x 5 cm x 5 cm = 125 cm3

Where cm3 is a volume unit.

Measuring Mass•Mass: How much matter in an object.• Units: kg, g, mg, ….

1 kg = 1000 g1g = 1000 mg

• Example: how many kilograms are in 6430 mg? 6.43 kg

• Density: is the mass per unit volume.

Density = massvolume

• What is the density of an object having a mass of 10g and a volume of 2 cm3 ?

Density = 10g = 5 g/cm3

2 cm3

The unit of density is g/cm3

Measuring Time and Temperature

• Time: the interval between two events. – The unit of time is the second

• Temperature: measured with a thermometer and measured in Celsius or Kelvin.• Celsius ranges from 0 (freezing) to 100

(boiling).• The Kelvin scale begins at absolute zero, or 0

K.• To convert to Kelvin you add 273 degrees to

the Celsius reading. • Freezing in Kelvin is 273 K, boiling is 373 K.

Scientific numbers use powers of 10

No decimalpoint

Zeros are not significant!

2 sig figs

DecimalPoint

All digits includingzeros to the left of

The decimal aresignificant.

6 sig figs

Zeros betweenNon zeros are

significant

All figures areSignificant4 sig figs

Zero to theRight of theDecimal aresignificant

All figures areSignificant5 sig figs

Zeros to the right ofThe decimal with no

Non zero values Before the decimalAre not significant

3 sig figs

Zeros to the right of the decimalAnd to the right of non zero values

Are significant

5 sig figs