Early Measurement History to Metric System

What Do the Following Terms Mean? Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement What Do the Following Terms Mean? The Cubit . . . The Fathom . . . The Hand/span . . . The Pace . . . The Foot . . . The Girth . . . The Palm . . .

Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement The Cubit The cubit was the measurement used by the Egyptians to build the pyramids. The cubit is the measure from your elbow to the tip of your middle finger when your arm is extended.

Early Measurement History The Fathom Gateway To Technology Unit 1– Lesson 1.3 – Measurement The fathom was used by seamen to measure the depth of water so that boats would not run aground and be stranded. The fathom is the measure from fingertip to fingertip when your arms are stretched sideways as far as they will go. You sometimes see a rope or fabric measured in this way.

Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement The Hand-span The hand-span was used to measure the height of horses. People still describe horses as being so many hands high. The hand-span is the measure from the tip of your pinky to the tip of your thumb when your hand is stretched out.

Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement The Pace This term was used by the Roman army to judge speed. The term is still used frequently during various types of foot races. The pace is the measure of distance from one step to another.

Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement The Foot A measurement equal to the length of an individuals foot. King Henry 1 standardized this measurement, because his foot was 12 inches long.

Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement The Girth Girth was a measurement often used to measure fishing line. The girth was the measurement around one’s stomach (your belt measure).

Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement The Palm The palm is the width of your four fingers when they are placed together.

Some folks found measuring in this fashion to be quite challenging. Early Measurement History Gateway To Technology Unit 1– Lesson 1.3 – Measurement Some folks found measuring in this fashion to be quite challenging.

Enter…The Metric System By the eighteenth century, dozens of different units of measurement were commonly used throughout the world. The lack of common standards led to a lot of confusion in trade between countries. At the end of the century, the French government sought to solve this problem.

Enter…The Metric System In 1790, the French National Assembly commissioned the Academy of Science to design a simple decimal-based system of units. The system they devised is known as the metric system. In 1960, the metric system was officially named the Système International d'Unités (or SI for short) and is now used in nearly every country in the world except the United States.

Enter…The Metric System The metre was originally calculated as one ten-millionth of the distance from the North Pole to the Equator through Paris, but it is now defined in terms of wave length.

STOP But…you say, we don’t use the metric system here in the US? Our distances are measured in miles, our paper in inches, our milk in gallons? Why? And is this right?

Now… we stop and debate!

Post Debate Okay…so since we have several systems of measurement in place We need to learn when to use which measurement And How to convert between all of them!

Why it is so important? CNN News Headline NASA: Human error caused loss of Mars orbiter November 10, 1999 WASHINGTON (AP) -- Failure to convert English measures to metric values caused the loss of the Mars Climate Orbiter, a spacecraft that smashed into the planet instead of reaching a safe orbit, a NASA investigation concluded Wednesday. The Mars Climate Orbiter, a key craft in the space agency's exploration of the red planet, vanished after a rocket firing September 23 that was supposed to put the spacecraft on orbit around Mars.   

The Seven Fundamental SI Units (le Système International, SI)

SI Prefixes Common to Chemistry Unit Abbr. Exponent Kilo k 103 Deci d 10-1 Centi c 10-2 Milli m 10-3 Micro  10-6

Metric to English Volume Distance 1 teaspoon = 4.9 milliliters 1 cup = 237 milliliters 1 pint = 473 milliliters 1 quart = 0.9 liters 1 gallon = 3.79 liters Distance 1 inch = 2.54 cm 1 foot = 0.3 meters 1 yard = 0.9 meters 1 mile = 1.6 kilometers Weight 1 ounce = 28.4 grams 1 pound = 0.5 kilograms 1 pound = 500 grams

Conversions in the metric system are merely a matter of moving a decimal point. The “base unit” means the you have a quantity (grams, meters, Liters, etc without a prefix.

Metric Conversions g m L 1000 100 10 0.1 .01 .001 kilo hecto deka Base unit deci centi milli 1 2 3 18 L 18 liters = 18 000 milliliters Example #1: Convert 18 liters to milliliters

Metric Conversions g m L 103 102 101 10-1 10-2 10-3 kilo hecto deka Base unit deci centi milli 3 2 1 450 mg = 0.450 g 450 mg Example #2: Convert 450 milligrams to grams

Metric Conversions g m L 103 102 101 10-1 10-2 10-3 kilo hecto deka Base unit deci centi milli 1 2 3 4 5 6 20 kg 20 kg = 20 000 000 mg Example #3: Convert 20 kilograms to milligrams