In this video you will learn about the metric system.

The metric system is used worldwide in order to measure length,mass, and volume time, current, and even luminosity.

The scientific community has adopted the metric system as their standard system of measurement.

In the United States the metric system seems a little odd because, the United States remains the only industrialized country that has not adopted the metric system as its official system of measurement.

- This allows for easy conversion among units, and insight into what is being measured.
- For example, 100 meters can easily be converted to centimeters by moving the decimal one place to the right, and the prefix " meters " indicates you will be measuring length.

*The base units of the metric system*The

**meter**is the standard unit for length. For example, if you see 1000 kilometers, the meters at the end of the word indicates that the measurement is of length.

The

**Liter**is a standard unit for volume.The

**Gram**is a standard unit for mass.

Again, the standard unit indicates the type of measurement.

- 12,234 kilograms will be a measurement of mass.
- .056 milliliters is measuring volume.
- 45 hectometers is measuring length

Since 1960 the metric system has been called the System of International Units and is abbreviated SI.

The SI has seven official units of measurement. Other units like the liter are accepted, but are not official. Here is a chart of the 7 SI units of measurement.

**Name Measures Abbreviation**

Meter length m

Kilogram mass kg

Second time s

Kelvin temperature K

Mole amount of a mol.

substance

Ampere electric current A

Candela luminous intensity cd

**The prefixes of the metric system**

The metric system also uses prefixes in order to make conversion between different measurements easy and accurate.

**The most common metric prefixes from largest to smallest.**

**Prefix Power Factor**

**kilo**10^3 1000

**hecto**10^2 100

**deka**10^1 10

**base unit ( meter liter gram)**

**deci**10^-1 .1

**centi**10^-2 .01

**milli**10^-3 .001

These are not the only prefixes used in the metric system. These six prefixes are taught most often in elementary,middle, and high school in the United States. In fact there are 24 prefixes in the metric system that range from the yotta ( 10^24) which is used for very large measurements, to the yocto (10^-24) which would measure incredibly small objects.However, for a beginners guide these seven prefixes are used most often.

An easy acronym for remember the metric prefixes is,

**King Henry Died By Drinking Chocolate Milk**

**kilo hecto deka base deci centi milli**

**or**

**Kangaroos Have Dirty Underwear During Cold Months**

**kilo hecto deka unit deci centi milli**

**Why are the prefixes in the metric system important?**

**Communication:**The prefixes allow people from all over the world to communicate about measurements. If someone in Japan sends an email to Europe, and tells them the inseam of the dress equals 120 centimeters, both people can easily understand this distance. This allows people in many diverse fields to communicate easily about measurements.

**Ease of Conversion**

**Because the metric system is based on factors of ten, conversion among the different size units can be quick and easy. Like many things in life there is a learning curve to conversion. If we start at a kilometer, and break it into 10 equal parts, then one of these equal parts is a hectometer. Subdivide the hecto meter into 10 equal parts, and one of these parts is a dekameter. A meter divided into 10 equal parts produces 10 centimeters, and so fourth. This allows you to convert among units by just moving a decimal point to the left or the right.**

**What does the meter,liter, and gram actually measure?**

**The standard for the**

**meter**, originally was equal to one ten-millionth the distance between the North Pole and the Equator on a meridian that passes through Paris. This distance from the North Pole to the equator worked out to be one fourth the circumference of the Earth. Today it is the length of the path traveled by light in a vacuum during a time interval of 1/299 792 458 of a second.

A

**liter**is equal to the volume of one cubic decimeter. Put another way, a liter is the volume of a cube with sides of 10 centimeters. Technically a liter is not an official SI unit, but is an accepted SI unit.

The official unit for volume is the cubic meter. (m^3)

A

**gram**is equal to the mass of one cubic centimeter of pure water at 39.2 degrees F ( 4 degrees C)

The official mass of a gram is 0.001 kilogram.

**Why the metric system? 5 reasons why I like the metric system**

**1.To bring order to chaos. The metric system was devised in France in the 18th century. At the time there was a mixture of measurements, and little organization. The goal of the metric system was to replace this disorganization with a system based on standard units and a decimal system.**

2. The metric system is used universally. The international scientific community has mandated the use of the metric system, and the US is one of the few industrialized countries that has not adopted the metric system.

3. It is easy to use. Because it is based on powers of ten, and has interrelated units it is easy to use. For example, compare the metric system to how I measure in Georgia. If I want to measure distance I could measure the distance in inches,feet,yards, or miles. None of these units give any clue that they are measuring distance. If I use the metric system I could measure in centimeters,decimeters,millimeters or kilometers. The term meter tells me it is measuring distance.

4. Less chance of mistakes. The use of decimals, and powers of ten make calculations easier and reduce the chance of errors.

5. Calculations are faster. Compare converting from Meters to millimeters 5 meters = 5000 mm

I simply move the decimal three places to the left.

Now convert yards to inches. 5 yards = 5 x 3 in order to convert to feet, then 3 x 12 in order to convert to inches. = 180

**Estimating with the metric system with common objects**

**Distance**

**Millimeter The width of a pencil is about 6 millimeters**

Centimeter The width of your pinky

Meter Distance from a doorknob to the floor

**Kilometer 60 % of a mile. A 10K running race is 6.2 miles**

**Volume**

**Milliliter A teaspoon is about 5 milliliters**

Liter A gallon of milk is almost 4 liters ( 3.78541 to be exact)

**Mass**

**Gram**One nickel 5 grams

**Gram**Can of tomatoes is about 500 grams

**Kilogram**Is roughly 2 pounds ( 2.20 pounds)

**Kilogram**Average laptop is about 2 kilograms

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