# The Metric System.

## Presentation on theme: "The Metric System."— Presentation transcript:

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) meter Volume (how much space it takes up) liter (for liquids) meter3 (for solids) Mass (how much matter is in it) gram Temp. (how much heat it has) °Celsius Time (how long it takes) second

How Do We Measure Them? (tools)
Length Temperature Volume Time Mass

Metric Prefixes kilo hecto deka deci centi milli 1000 100 10
1/ (0.1) 1/ (0.01) 1/1000 (0.001) BASE UNIT

Moving the Decimal for Length
Larger Units, Smaller Number Smaller Units, Larger 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 has to do with what’s inside an object (matter), so it won’t change, no matter where you go. Mass is NOT the same as weight!

Let’s make it easier What’s a gram? About the mass of a paperclip What’s a kilogram? About the mass of 2 loaves of bread How do kilograms compare to pounds? 1 kg = about 2.2 pounds

Moving the Decimal for Mass
Larger Units, Smaller Number Smaller Units, Larger 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 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

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.

Moving the Decimal for Volume
Larger Units, Smaller Number Smaller Units, Larger 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 Mass and then skip 5 lines Write Volume of a liquid and then skip 5 lines Write 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)

Density For liquids or oddly-shaped solids, we use a triple beam balance to find the mass in grams and a graduated cylinder to find the volume in mL. For easy-to-measure solids (like a cereal box), we use a triple beam balance to find the mass in grams and a ruler to find the volume in m3 .

Density More packed = More dense 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. Water has the density of 1 g/mL Any object with a larger density (greater than 1 g/mL) will sink. Any object with a smaller density (less than 1 g/mL) will float.

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

Density REMEMBER: 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, Rubbing Alcohol (green), Cooking Oil, and Dish Soap