The Metric System

The Metric System• All scientific measurements are made using

the Metric System.• It is also called the SI System

(La Systeme International d’Unites)• The United States is the only major country

that does not use this system.

Very Easy To Use

There are base units and prefixes Based on 10 (10 and 100 and 1,000) so you

multiply or divide by 10 when converting It’s a decimal system… Can you think of a

system we use every day that is a decimal system? ___________

Hint

Metric Base Units(last names)

Length (how long it is) meterVolume (how much space it takes up) liter (for liquids)

meter3 (for solids)

Mass (how much matter is in it) gramTemp. (how much heat it has) °Celsius

Time (how long it takes) second

How Do We Measure Them? (tools)

LengthTemperature

Volume

TimeMass

Metric Prefixes

kilohectodeka

decicentimilli

1000 100 10

1/10 (0.1) 1/100 (0.01) 1/1000 (0.001)

BASE UNIT 1

Moving the Decimal for Length

Smaller Units, Larger Number

Larger Units, Smaller Number

Base Unit

kilo(km)

Hecto(hm)

Deka(dka)

METER(m)

Deci(dm)

Centi(cm)

Milli(mm)

Let’s make it easier

What’s a millimeter ? About the thickness of a paperclip

What’s a centimeter? About the width of your pinkie finger

What’s a meter? Height from the floor to the door knob

The length of the yellow line in centimeters (there will be a decimal) is _______ cm

The length of the yellow line in millimeters (there will not be a decimal) is _______ mm

Mass• The mass is the amount of matter (or

stuff) in an object and never changes unless you change the object.

• We use a triple beam balance to find the mass of an object in grams.

Mass vs. Weight

• The weight of something is the amount of gravity pulling down on an object and will change if you go somewhere with more or less gravity.

• Mass is NOT the same as weight!

Moving the Decimal for Mass

Smaller Units, Larger Number

Larger Units, Smaller Number

Base Unit

kilo(kg)

Hecto(hg)

Deka(dkg)

GRAM(g)

Deci(dg)

Centi(cg)

Milli(mg)

Use the triple beam balance to find the mass of a football in grams?

Volume• The volume is the amount of space an

object takes up.• For liquids or oddly-shaped solids, we use a

graduated cylinder or beaker to find the volume in liters (or mL).

Volume• The surface of the liquid might look

slightly curved.• This curve is called the meniscus and we

read the amount of mL from the lowest point of the meniscus.

glug, glug, glug

Volume• For easy-to-measure solids (like a cereal

box), we use a rule to find the volume in cubic meters (m3).

• Volume (m3) = Length x Width x Height

boom,boom,boom

Moving the Decimal for Volume

Smaller Units, Larger Number

Larger Units, Smaller Number

Base Unit

kilo(kL)

Hecto(hL)

Deka(dkL)

LITER(L)

Deci(dL)

Centi(cL)

Milli(mL)

Use the meniscus (lowest point of the water’s surface) to find the volume of the water (there will be a decimal). The volume is about _______ mL.

Measuring Mass and Volume• Take out a new piece of paper and do the

following:

• Put your name and hour in the top right hand corner

• Write 1. Mass and then skip 5 lines

• Write 2. Volume of a liquid and then skip 5 lines

• Write 3. Volume of a solid and then skip 5 lines

Density• Density is the amount of matter

(mass) per given space (volume)

• Density = Mass (g) ÷ Volume (mL or cm3)

• For example, water’s density is 1 g/mL which means that there is 1 gram of matter in every mL of water.

Density

Think of it like a suitcase…the more clothes you try to fit in a suitcase, the more packed it gets.

More packed = More dense

Density

When you compare the density of two or more objects, the denser objects will sink below the less dense objects.

For example, if an object has a density of 2 g/mL … what will it do in water? What if an object has a density of 0.2 g/mL?

Density

• EXAMPLE OF SAME MASS (151 g):Spongebob Mac & Cheese

Easter jelly beans

• EXAMPLE OF SAME VOLUME (5,452 cm3):Red Swirly bowling ball Spider Web bowling ball

DensityREMEMBER: Denser objects sink below less dense objects!

• Number your paper 1 – 5

• Order the following objects from least dense (#1) to most dense (#5):

• Water (blue), Syrup, Oil, Rubbing Alcohol (green), Oil, and Dish Soap