What you need to know

• First things first, you need to understand the basics

• There are two systems of measurement– US/Customary System which we use here – Then there is the metric system which is used

all over the world

Measurement Basics

• Length: is the distance of something measured

• Volume/Capacity: how much something can hold ( generally liquid)

• Weight: how much something weighs

• Mass: how much space something takes up

US/Customary System

• The US/Customary system has many different units of measurement

• Each unit has a completely different name

• They also have completely different conversion factors

Metric System

• The metric system has base unit and many different prefixes

Metric Base Units of Measurement

• Meters: Measures length – the distance of something

• Liters: Measures volume or capacity –how much something can hold (generally

liquid)

• Grams: measures weight/mass –how much something weighs or how much

space sometime takes up

Metric System

• So if you needed to measure length you would choose meter as your base unit.

–Length of a pencil

•0.1 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 10 miles from school

• 10 miles = 16093 meters

–16093 is a big number.

–The metric system has prefixes that you can add to the base unit to make it easier to manage:

Metric System• The three prefixes that we will use the most

are:– kilo– centi– milli

kilo hecto deca

Base Unitsmetergramliter

deci centi milli

Metric System Prefixes• Mili- 1/1000, which means that

1000mm=1m• Centi- 1/100, which means that 100cg=1g• Deci- 1/10, which means that 10dl=1l• Deka- 10, which means that 1dkm=10m• Hecto- 100, which means that 1hg=100g• Kilo- 1000, which means that 1kl=1000l

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

– Centimeters are 10 times larger than millimeters so it takes more millimeters for the same length

1 centimeter = 10 millimeters

Example not to scale

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 cm

40

41

41

40

Units of Measurement:Volume

• US System– Cups– Pints– Quarts– Gallons– Fluid Ounces

• Metric System– Liters

Units of Measurement:Length

• US System– Inches– Feet– Yards– Miles

• Metric– Meters

Units of Measurement:Weight/Mass

• US System– Ounce– Pound– Tons

• Metric– Gram

1 liter of water weighs 1 kilogram, so 1 cubic meter — 1000 liters — of water weighs 1000 kilograms or 1 metric ton

• A US cent weighs exactly 2.5 g, while the nickel weighs exactly 5 g.

• A doorknob is typically about 1 m high.

• The diameter of a CD or DVD is 12 cm.