METRIC SYSTEM

WHAT is the METRIC SYSTEM?

• Called the INTERNATIONAL SYSTEM OF UNITS.

• Used in every country but the United States, Liberia and Burma

• Other countries’ companies are refusing to buy products from the U.S. if not labeled in metric units

• Scientists need a universal way to communicate data (SI Units) with others from different parts of the world.

WHY SHOULD THE UNITED STATES USE THE METRIC

SYSTEM?

What are the “BASIC UNITS” within the METRIC SYSTEM?

•METERS – Length or Distance

•GRAMS – Mass or Weight •LITERS – Volumes of Liquid, Solids or Gases

How does the METRIC SYSTEM

work?

The metric system is based on the units of

10’s.

•10 milligrams equals 1 centigram•10 centigrams equals 1 decigram•10 decigrams equals 1 gram•10 grams equals 1 decagram•10 decagrams equals 1 hectogram•10 hectogram equals 1 kilogram

EXAMPLE: MASS AND WEIGHTS

THE BASIC UNIT OF MEASURE FOR LENGTH AND

DISTANCE IS THE

METER

What instrument do we use to measure LENGTH?

•To measure length we use a METER STICK.

What is the difference between a yard stick and a meter stick? They both look

the same.

The METER STICK has more numbers so therefore more accurate than a yard stick

WHAT ARE THE PARTS OF A METER STICK?MILLI-METERS

10 MILLI-METERS equals 1 CENTI-METER

10 CENTIMETER equals

1 DECIMETER

10 DECIMETERS equals 1 METER

•10 METERS equals 1 DEKA-METER

•10 DEKA-METERS equals 1 HECTO-METER

•10 HECTO-METERS equals 1 KILO-METER

What is the numeric difference between the units of measures?

• One millimeter is .001 because there are 1000 millimeters in a meter.

• One centimeter is .01because there are 100 centimeters' in a meter.

• One meter is 1.0 because there is 1 meter to a meter

• One kilometer is 1000.0 because there are 1000 meters in a kilometer.

How do I use a METER STICK?

1.Determine which unit of measure you will be using.

2.Place the 0 end of meter stick at the edge of the object you wish to measure, making sure that the object is at the beginning of the measurements on the meter stick. Disregard any spaces to the left of any 0.

3.Make a note of where the measurement stops. For example: If the measurement ends on a millimeter tick mark, count the total meters, then the centimeters‘ past the meter marks then any millimeters past the centimeter mark.

4.Make sure the decimal places are in their right spot.

THE BASIC UNIT OF MASS AND WEIGHT

THE GRAM

MASS•To measure MASS we use a TRIPLE BEAM BALANCE

WEIGHT•To measure WEIGHT we use a SCALE

•10 milligrams equals 1 centigram•10 centigrams equals 1 decigram•10 decigrams equals 1 gram•10 grams equals 1 decagram•10 decagrams equals 1 hectogram•10 hectogram equals 1 kilogram

MASS AND WEIGHTS

HOW DO YOU USE A TRIPLE BEAM BALANCE?

With the pan empty, move the three sliders on the three beams to their leftmost positions, so that the balance reads zero. If the indicator on the far right is not aligned with the fixed mark, then calibrate the balance by turning the set screw on the left under the pan.

calibrate

Once the balance has been calibrated, place the object to be

measured on the pan.

Move the 100 gram slider along the beam to the right until the indicator drops below the

fixed mark. The notched position immediately to the left of this point indicates

the number of hundreds of grams.

100 gram slider

(middle)

Now move the 10 gram slider along the beam to the right until the indicator drops

below the fixed mark. The notched position immediately to the left of this point indicates

the number of tens of grams.

10 gram slider

(back)

The beam in front is not notched; the slider can move anywhere along the beam. The boldface numbers on this beam are grams and the tick marks between the boldface

numbers indicate tenths of grams.

10th of GRAMS Slider

(front)

To find the mass of the object on the pan, simple

add the numbers from the three beams.

To find the mass of the object on the pan, simple

add the numbers from the three beams.

As with a ruler, it is possible to read the

front scale to the nearest half tick mark.

THE BASIC UNIT OF MEASURE VOLUME OF SOLIDS, LIQUIDS

AND GASSES

LITER

•10 milliliters equals 1 centiliter•10 centiliters equals 1 deciliter•10 deciliters equals 1 liter•10 liters equals 1 decaliter•10 decaliters equals 1 hectoliter•10 hectogram equals 1 kiloliter

MASS AND WEIGHTS

To measure the volumes of liquids, solids and gasses we use a GRADUATED CYLINDER.

PARTS OF A GRADUATED CYLINDER

Bumper - Keeps the cylinder from breaking if it’s knocked over.

STAND

TUBE – May be glass or plastic

BEAK – Makes it easy to pour liquids

GRADUATED CYLINDER MEASURES

MILILITERS

10th of a milliliter

How do you read a GRADUATED CYLINDER?

•Measuring with a graduated cylinder is complicated somewhat by a meniscus. 

A meniscus is the curvature of the

surface of the water.  Water "sticks" to the

walls of the graduated cylinder, but only on the sides and not the

middle. 

• Because of the meniscus, when you look at the surface, the water level is not straight

• Measurement should be at the lowest point of the meniscus.

• You need to read the meniscus at eye level in order to get an accurate reading.

• You should place the graduated cylinder on the table and then lower your head to be able to read the meniscus at eye level.

What is the measure of this liquid?

40.8 ml

What is VOLUME?

VOLUME is the amount of space an object occupies.

How do I find the VOLUME of an irregular shaped

object using a graduated cylinder?

1. Fill the graduated cylinder to 50 ml. Make a note of this measurement.

2. You may have to fill the graduated cylinder to a higher level to completely submerge an object. In this case your beginning volume will change to the level you started with.

3. Slide the object down the side of the cylinder until it is completely submerged in water.

4. Make a note of this measurement.

5. Subtract the starting measurement from the ending measurement and you’ll have the volume of the irregular shaped solid.

How do I find the VOLUME of an regular shaped

object?

Use the mathematical formula:

length X width X height = V³

length

width

height