READ: History & Uses
In the United States, we know there are 12 inches in 1 foot and 3 feet make 1 yard. We also say there are 16 ounces in 1 pound and 2,000 pounds in 1 ton. These measurements are all part of the system of U.S. Customary Units that was developed from the original system of English Units. Americans grow up learning these definitions but the measurements and ratios are completely random and are not used in other countries.
In most of the world, the modern metric system reigns supreme. Officially known as Le Système International d'Unités, or the International System of Units, it is more simply known by its abbreviated name, the SI. This modern version of the metric system has failed to officially become the standard measurement system in the United States, but it is used consistently by those in science, medicine, government, military, and many sectors of industry. The U.S. is one of only three nations (the others being Liberia and Myanmar) that have not adopted the SI as their official system of weights and measures but we still use it every day!
While some form of the metric system has been around since it was developed in France in the 1790s, the modern SI form was introduced in 1960. In 1968, the U.S. Congress authorized a study to examine a process for converting to the new system. The study found that, in many cases, private U.S. corporations that do business with other countries had already adopted the metric system. In 1975, President Gerald Ford signed the Metric Conversion Act into law, formally adopting the metric system as the “preferred system” for U.S. trade and commerce. Then the U.S. government passed the Omnibus Trade and Competitiveness Act of 1988, which made the metric system "the preferred system of weights and measures for U.S. trade and commerce." The legislation states that the federal government has a responsibility to assist industry as it voluntarily converts to the metric system. This is most evident in U.S. labeling requirements on food products, where SI units are almost always presented alongside customary units.
So, if the U.S. government has supported a shift to the SI multiple times, why do we still use the customary units? It is common for people to say the metric system is not used in the United States but take one look at a nutrition label or a mechanical pencil and you will realize that we do, in fact, use metric measurements! Nearly all countries use a mix of metric units and their own, traditional units. Our country does the same and metric is preferred in many professions but we have not adopted the SI as our official, overall system.
In the United States, we know there are 12 inches in 1 foot and 3 feet make 1 yard. We also say there are 16 ounces in 1 pound and 2,000 pounds in 1 ton. These measurements are all part of the system of U.S. Customary Units that was developed from the original system of English Units. Americans grow up learning these definitions but the measurements and ratios are completely random and are not used in other countries.
In most of the world, the modern metric system reigns supreme. Officially known as Le Système International d'Unités, or the International System of Units, it is more simply known by its abbreviated name, the SI. This modern version of the metric system has failed to officially become the standard measurement system in the United States, but it is used consistently by those in science, medicine, government, military, and many sectors of industry. The U.S. is one of only three nations (the others being Liberia and Myanmar) that have not adopted the SI as their official system of weights and measures but we still use it every day!
While some form of the metric system has been around since it was developed in France in the 1790s, the modern SI form was introduced in 1960. In 1968, the U.S. Congress authorized a study to examine a process for converting to the new system. The study found that, in many cases, private U.S. corporations that do business with other countries had already adopted the metric system. In 1975, President Gerald Ford signed the Metric Conversion Act into law, formally adopting the metric system as the “preferred system” for U.S. trade and commerce. Then the U.S. government passed the Omnibus Trade and Competitiveness Act of 1988, which made the metric system "the preferred system of weights and measures for U.S. trade and commerce." The legislation states that the federal government has a responsibility to assist industry as it voluntarily converts to the metric system. This is most evident in U.S. labeling requirements on food products, where SI units are almost always presented alongside customary units.
So, if the U.S. government has supported a shift to the SI multiple times, why do we still use the customary units? It is common for people to say the metric system is not used in the United States but take one look at a nutrition label or a mechanical pencil and you will realize that we do, in fact, use metric measurements! Nearly all countries use a mix of metric units and their own, traditional units. Our country does the same and metric is preferred in many professions but we have not adopted the SI as our official, overall system.
Our customary units may be here to stay because old habits die hard. However, the metric system is so much easier! The metric system solved many problems by:

WATCH: Metric Videos
Neil deGrasse Tyson  Metric Uses

National Institute of Standards & Technology

Intro to Metric Unit Conversions

Measuring Devices:
The Ruler shows a blue line at 3.6 centimeters. That could also be reported as 36 millimeters. The Digital Scale measured the mass of a calculator to be 90.77 grams. That could also be reported as 0.09077 kilograms. The Graduated Cylinder is filled with 43 milliliters of water. That could also be reported as 0.043 Liters. 
PRACTICE: Metric Conversions
Metric units are nice to work with because they are all multiples of 10 apart from each other. Therefore, converting between the units simply requires moving the decimal point!
The primary base units are meters, liters, grams, and seconds but adding a prefix to those base units either increases or decreases the size of the measurement. There are many metric prefixes, but the main prefixes are:
kilo hecto deka [base unit] deci centi milli
Convert from one prefix to the next by simply moving the decimal! For example: 15 meters would be 1500 centimeters because the decimal must be moved two places to the right (centi is two "jumps" right of the base unit). By moving towards centimeters the unit became smaller so the actual number became bigger! 100 times bigger!
Use the Metric Conversion Chart shown above!
Practice #1: Convert 12.54 kilometers to centimeters.
How many jumps is it from "kilo" to "centi"? Five, to the right.
So move the decimal point five places to the right, filling in the extra space with zeros:
Practice #2: Convert 457 milliliters to hectoliters.
How many jumps is it from "milli" to "hecto"? Five, to the left.
So move the decimal point five places to the left, filling in the empty spaces with zeros:
Final answer: 0.00457 hectoliters
Practice #1: Convert 12.54 kilometers to centimeters.
How many jumps is it from "kilo" to "centi"? Five, to the right.
So move the decimal point five places to the right, filling in the extra space with zeros:
 Final answer: 1,254,000 centimeters
Practice #2: Convert 457 milliliters to hectoliters.
How many jumps is it from "milli" to "hecto"? Five, to the left.
So move the decimal point five places to the left, filling in the empty spaces with zeros:
Final answer: 0.00457 hectoliters
Online Practice:
Think you've got it? Play this game to see if you can convert between metric units: Build a Shed Game
Try this online practice quiz to test your understanding of metric conversions: Metric Conversions Online Practice Quiz
Think you've got it? Play this game to see if you can convert between metric units: Build a Shed Game
Try this online practice quiz to test your understanding of metric conversions: Metric Conversions Online Practice Quiz
ANSWER: Discussion Questions
Write your responses and submit to Ms. Hinkhouse
Write your responses and submit to Ms. Hinkhouse
 Find five different items in your house (not all food) that have both a U.S. Customary Unit and a Metric Unit listed (ex: a water bottle labeled as 16.9 ounces or 500 mL). Describe each item and write down both measurements.
 The Metric Unit Conversions video posted to this page used a silly sentence to remember the order of metric prefixes. Come up with your own school appropriate sentence to remember the prefixes and write it down! (it would be great if your sentence helped to differentiate between the "deka" and "deci" prefixes)
 Do some research: when is National Metric Day? Knowing what you know about the metric system, why does it make sense to have it on that date? Explain.
 What do you believe is the biggest roadblock to the U.S. completely switching to metric? Provide evidence to support your claim.
 Read this article about how metric measurements could protect the lives of children. Write a 3 to 5 sentence summary paragraph of the article AND a 3 to 5 sentence reflection paragraph (the reflection can explain your thoughts or describe your experiences with the issue).
Submit your answers to Ms. Hinkhouse and you will receive the required Metric Conversions Practice Sheet!
ASSESS:
Once you have completed and submitted the Discussion Questions AND Metric Conversions Practice Sheet, schedule a time for a closednotes quiz over the three Learning Targets listed at the top of this page.
Once you have completed and submitted the Discussion Questions AND Metric Conversions Practice Sheet, schedule a time for a closednotes quiz over the three Learning Targets listed at the top of this page.