Introduction and History The Metric System Introduction and History

Why Metric? Countries wanted “standards” for measuring things A standard unit is an exact quantity used as a reference point for measurements (Meter, Gram, Liter) A standard is used throughout the world

Standards in History Kings used to use their body parts to determine units of measurement. Ex. The standard yard was the distance from the king’s nose to his outstretched arm.

Kings used feet to measure distance. This is how the term “foot” came about. Today the standard “foot” in the English system is 12 inches.

English system is very confusing because it has too many different values.

The United States is the only major country that still uses the old English system. (also called the Imperial System)

The Great Mars Mistake Two different groups of scientist were working in the calculations to send a probe to Mars. The American team did their calculations in the English standard and the other team did it in the metric system. (OOPS!)

Results were Devastating This made scientists very upset. It cost the space program $125 million. It cost the scientist their time and effort.

Scientist around the world give the English system the thumbs down. Scientist needed an exact and uniform system of weights and measurements to be used throughout the world.

How did the metric system come about? During the 18th century scientist created a system of measurements to be used world wide. This is how they came up with the length of the standard meter.

History of the Meter Scientist measured the distance from the equator to the North Pole and divided that into ten million equal parts. This was called the 1-meter. The original meter is kept in a safe in France. A Meter stick is an exact copy of that standard. A meter is divided into 100 equal parts called “centimeters” and 1000 equal parts called “millimeters.”

History of the Liter Scientists needed a way to measure liquids so they took 10cm and multiplied it by its length x width x height to come up with a standard for measuring volume. The liter is the size of 10 cm3 10cm x 10cm x 10cm Length x Width x Height = Volume The liter is used to measure liquid volumes

The History of the Gram Scientist needed a standard to measure mass. Mass is the amount of matter in an object. They weighed one cubic centimeter of water and called it a gram.

The History of the Second Early astronomers defined 1 second as 24- hours divided by 360. In 1967, scientists redefined it as the time needed for a Cesium atom to vibrate 9.2 billion times.

Metric Prefixes “Kilo” means thousand (1000) “Hecto” means hundred (100) “Deka” means ten (10) Base unit “Deci” means one-tenth (1/10) “Centi” means one-hundredth (1/100) “Milli” means one-thousandth (1/1000)

Metric Word Endings (Bases) “Meter” – Measures Length “Liter” – Measures Volume (how much space something takes up) “Gram” – Measures mass (how much matter is in an object)