The Metric System

1. The Metric System If you can understand and use: pounds, inches, gallons, or Fahrenheit, you can learn the metric system

2. Why Metric? • A basic understanding of metric units and usage is a necessary part of being educated and literate. • While traditional units of measure are still in widespread use in the United States and in certain other places, metric is the standard. • It is practically everywhere and it seems the direction that the whole world is moving towards more and more. You will see it often throughout your lives.

3. Why Metric? • The metric system is simpler and easier to use and understand than traditional measurement systems. • Because metric uses prefixes, there is effectively a single unit for all measurements of a certain kind (such as length or volume). • Using metric units in many cases would greatly improve communication and comprehension. • Converting to the metric system, does not need to be overly expensive, and often it is costly to not to do so. • A number of countries already prohibit the importation of products with any non-metric indications on the labels, and more countries will follow. • If a company must carry two different product lines just to have metric sizes in one country and non-metric in another, that is wasteful and unnecessary.

4. Why Metric? • It is inevitable, ultimately. The world has decided on metric. At the moment, about 95% of the population of the world lives in a country that is metric or getting close. • These people represent 70-80% of the world economy, a figure which has been rising for 60 years.

5. Learning Metric • If you can understand and use pounds, inches, gallons, or Fahrenheit, you can learn metric. • The metric system is not hard to learn—most people just try to learn it the hard way.

6. Rule #1: Don't try to do conversions between metric and non-metric. • Forget about the old units for now. If I weigh myself and find that I am 65 kilograms, then I now have an idea of what 65 kg means. There’s no need to know what that is in pounds. • I also know that a 0.5 liter bottle full of water weighs half a kilogram. Now I have some reference points to build a mental framework for what a kilogram means. • It doesn't mean a certain number of pounds; it means a weight that can be related to our own experience.

7. Rule #2: Metric does not necessarily mean "math problems". But if you do need to do some arithmetic involving measurements, there's no better way. • Do you have to do math problems when you buy a gallon of milk or look at a thermometer that shows Fahrenheit? Of course not. Then why would you need to know lots of math to buy a two-liter bottle of Sprite or look at a Celsius thermometer? • For situations where you do need to use math, using metric units in math is much easier than using the standard units.

8. Rule #3: Be prepared for some mental discomfort. • If you are not familiar with using a particular unit of measure, it can seem like gibberish. IT’S OK! • Relating that a mental picture can involve some effort and feelings of uncertainty. IT’S OK! • Keep in mind that most people aren't experts in the non-metric units either. For example, suppose you can see a street sign. You may not be able to say if it is 100 meters away or 150, but how accurate would you be if you tried to estimate it in feet?

9. Reference Points • Learning metric really only requires a few reference points and a way to use them in everyday life. • To help me use metric units, I have a Celsius thermometer, a kilogram scale, a liter water bottle, several meter sticks, and a metric odometer and speedometer on my bike. • The first three are available at Walmart, the meter sticks are available online from Office Depot, and you can get a bike computer at any bike shop. • When you get a thermometer or scale, get a digital one because these will let you to show only the metric units. It is much easier to think in the new units if you don't have the old ones around.

10. Overview of Important Metric Units • You may come across metric units of measure with which you are unfamiliar. THAT IS OK! • This part of class is intended to introduce you to the metric units that a literate person might be expected to know or which you may come across in your lifetime.

11. THIS SHOULD GO IN JOURNAL ENTRY #1 Overview of Important Metric Units • What are you measuring? What units will you be using? • Length • Units used: kilometer, meter, centimeter, millimeter, sometimes others • Area • Units used: any of the above squared, also hectare (ha) • Volume • Units used: cubic meter, liter, milliliter • Mass • Units used:("weight")metric ton, kilogram, gram, milligram, microgram • Force • Units used: Newtons • Pressure • Units used: bar, millibar or hectopascal, pascal • Temperature • Units used: Celsius, Kelvin

12. Descriptions of Metric Units *These prefixes have limited usage. You will usually only see them in the centimeter, hectopascal, and hectare. **The SI Brochure spelling of this prefix is deca-, but the U.S. National Institute of Standards and Technology (NIST) recommends deka-

13. Length • The length units are probably what most people think of when they think of the metric system, so most people are probably fairly familiar with them. • A meter is about the distance from the floor to a doorknob. Sometimes, you may see a kilometer informally referred to as a "klick".

14. 1 mile 1.6 kilometers 1 yard = 0.9444 meters 1 inch = 2.54 centimeters English vs. Metric Units Which is longer? A. 1 mile or 1 kilometer B. 1 yard or 1 meter C. 1 inch or 1 centimeter Left Image: http://webapps.lsa.umich.edu/physics/demolab/controls/imagedemosm.aspx?picid=1167Right Image: http://share.lancealan.com/N800%20ruler.jpg

15. A. 1 meter or 105 centimeters B. 4 kilometers or 4400 meters C. 12 centimeters or 102 millimeters D. 1200 millimeters or 1 meter km Metric Units m cm mm The basic unit of length in the metric system in the meter and is represented by a lowercase m. Standard: The distance traveled by light in absolute vacuum in 1⁄299,792,458 of a second. Metric Units 1 Kilometer (km) = 1000 meters 1 Meter = 100 Centimeters (cm) 1 Meter = 1000 Millimeters (mm) Which is larger?

16. 1 centimeter = 10 millimeters What is the length of the line in centimeters? _______cm What is the length of the line in millimeters? _______mm What is the length of the line to the nearest centimeter? ________cm HINT: Round to the nearest centimeter – no decimals. Measuring Length How many millimeters are in 1 centimeter? 2.8 28 3 Ruler: http://www.k12math.com/math-concepts/measurement/ruler-cm.jpg

17. Area • To specify area, use square meters (m2), hectares (ha), or square kilometers (km2). • A hectare is the area of a square 100 m on a side, which means it is 10,000 m2. There are 100 ha in one km2. A hectare covers about two and a quarter football fields. • With the metric system it is easy for farmers and others to figure out how much water covers how much area. • For example, one liter of water covers one square meter to a depth of one millimeter. So, 10 cm of water that covers 1 m2 is 100 L. • Likewise, 1 mm of water covering 1 ha equals 10,000 L, and 1 mm of water over 1 km2 equals 1 million liters.

18. Volume • You may already be familiar with liters and milliliters. • Just as there are 1000 milliliters in one liter, there are 1000 liters in one cubic meter. • In various metric areas of the world, prefixes besides "milli" are often used with liters. So in France you may find a bottle labeled in centiliters, and in Australia you may get a water bill showing your consumption in kiloliters, or see a news report mentioning megaliters.

19. 1 fl oz = 29.573 ml 1 12-oz can of soda would equal approximately 355 ml. 1 quart = 0.946 liters 1 gallon = 3.79 liters It would take approximately 3 ¾ 1-liter bottles to equal a gallon. English vs. Metric Units Which is larger? A. 1 liter or 1 gallon B. 1 liter or 1 quart C. 1 milliliter or 1 fluid ounce

20. kL Metric Units cL mL L Volume is the amount of space an object takes up. The base unit of volume in the metric system in the liter and is represented by L or l. Standard: 1 liter is equal to one cubic decimeter Metric Units 1 liter (L) = 1000 milliliters (mL) 1 milliliter (mL) = 1 cm3 (or cc) = 1 gram* Which is larger? A. 1 liter or 1500 milliliters B. 200 milliliters or 1.2 liters C. 12 cm3 or 1.2 milliliters* * When referring to waterLiter Image: http://www.dmturner.org/Teacher/Pictures/liter.gif

21. What causes the meniscus? A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides. Measuring Volume We will be using graduated cylinders to find the volume of liquids and other objects. Read the measurement based on the bottom of the meniscus or curve. When using a real cylinder, make sure you are eye-level with the level of the water. What is the volume of water in the cylinder? _____mL Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gifBottom Image: http://morrisonlabs.com/meniscus.htm

22. Measuring Liquid Volume What is the volume of water in each cylinder? Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf A B C Pay attention to the scales for each cylinder.

23. 9 cm 8 cm 10 cm We can measure the volume of irregular object using water displacement. Amount of H2O with object = ______About of H2O without object = ______Difference = Volume = ______ http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/en/syllabus/unit14/new/testingmain1.htm Measuring Solid Volume We can measure the volume of regular object using the formula length x width x height. _____ X _____ X _____ = _____

24. Mass (weight?) • Weight really means the Mass multiplied by the Force of Gravity. (on earth it is 9.8m/s/s) • Weight = Mass X Gravity • Mass measures come in multiples of 1000: • a thousand milligrams per gram, • a thousand grams per kilogram, etc. • Water weighs one gram per milliliter, one kilogram per liter, and one metric ton per cubic meter. • You have seen medicine and vitamins labeled in milligrams, and perhaps in micrograms well.

25. 1 pound = 453.6 grams 1 ounce of gold = 28,349.5 milligrams 100 kilogram = 220 pounds English vs. Metric Units Which is larger? 1. 1 Pound or 100 Grams 2. 1 Kilogram or 1 Pound 3. 1 Ounce or 1000 Milligrams

26. Kilogram Prototype A. 1 kilogram or 1500 grams B. 1200 milligrams or 1 gram C. 12 milligrams or 12 kilograms D. 4 kilograms or 4500 grams kg Metric Units cg mg g Mass refers to the amount of matter in an object. The base unit of mass in the metric system in the kilogram and is represented by kg. Standard: 1 kilogram is equal to the mass of the International Prototype Kilogram (IPK), a platinum-iridium cylinder kept by the BIPM at Sèvres, France. Metric Units 1 Kilogram (km) = 1000 Grams (g) 1 Gram (g) = 1000 Milligrams (mg) Which is larger? Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram

27. Weight • To understand body weight in kilograms, it is best to get a scale (or change the setting on yours if you can). These can be some reference points: • A Newborn baby 2500 - 4000 g (2.5 - 4.0 kg) • A Lightweight adult 55 - 75 kg • A Medium-weight adult 70 - 100 kg • A Really big football player 140 kg • If you get a scale, you can weigh yourself with and without a backpack full of books or other items to find out how much the backpack weighs.

28. Force • The metric unit for force is the Newton (N). • This is one area that may seem less familiar to newcomers to the metric system. • Normally, you won't have to worry about Newtons, but they do come up in a few situations. For example, the lift on the back of a truck may have its capacity measured in Newtons. • A Newton is about the weight of 100 grams. • So, an apple weighs about 1 N. • A good rule of thumb is that an object's weight in Newtons is ten times its mass (weight) in kilograms. • So, if a person is about 59 kg, they weigh approximately 590 N.

29. Pressure • The measurement of pressure can seem bewildering at first glance, because there are so many units that have historically been used. • However, there are now just two metric units that are generally used, and they are closely related: the Pascal and the bar. • The modern unit for pressure is the Pascal (Pa). • The Pascal is a very small unit, so people often use another unit called the bar, which is defined to be 100,000 Pa. • The bar is demonstrating the pressure of the atmosphere, hence its name (the barometric pressure). • In weather reports, pressure is usually given in millibar (mb or mbar) or hectopascal (hPa). They both the same: 100 Pa. • Sometimes, pressure is given in kilopascals (kPa). • Air pressure is normally in the range of 980 mb to 1030 mb.

30. Temperature • In everyday life, we measure temperature in degrees Celsius when we use metric, of course. • For scientific measurements, or for very hot or cold things, we may use Kelvins (such as for the temperature of the sun or of liquid helium). • Kelvin is like Celsius, but shifted so that zero is at absolute zero instead of the freezing point of water. • Water freezes at 273.15 Kelvins. Incidentally, we do not speak of degrees Kelvin—it's just Kelvins. • To understand the basics of Celsius temperatures just remember:Thirty's warm,Twenty's nice,Ten's cold,Zero's ice. • That is really all you need to know most of the time, except perhaps the boiling point of water (100 °C) and body temperature (37 °C).

31. Height • To understand a person's height in centimeters, it is best to tape a meter stick to the wall so you and others can measure the height directly. These can be some reference points: • New-born baby (length) 50 cm • Average man (18 yrs. old) 177 cm (90% are between 167 and 185 cm) • Average woman (18 yrs. old) 164 cm (90% are between 156 and 171 cm) • Tall basketball player 200 cm (2 meters)

32. Millimeters • One very simple thing you can do to begin using millimeters is to change your word processor, and other software on your computer, to use millimeters instead of inches. • After a few weeks of using 20 mm margins or 25 mm margins, it feels completely natural to use mm instead of using inches.

33. Small volumes and weights • I recently got a kitchen food scale that shows weights up to 2 kg. Now I can know that I ate 100 g of pasta (before cooking) last night! • One thing you can do right now to help you understand grams is to look at the package for a loaf of bread. The serving size will probably be one slice, with a weight in grams given. If you get out a slice and see how heavy it feels, you have a reference point right there in your kitchen. • When you go to the grocery store, instead of looking at the ounces or fluid ounces on the label, pay attention to the milliliters (mL), liters (L), grams (g), and kilograms (kg). • If you have a water bottle that is either 500 mL or 1 L, you can just look at the size of the bottle an get an idea of how much those quantities are. The two liter soda bottle can also serve as a reference point. • If you have a box of cereal that weighs 425 g, you just see how heavy the box feels to get an idea of how much 425 g is.

34. Elevation (distance above sea level) • Compare the elevation of your town (Shelley, Idaho(1,412 m) to these values: • U-2 Spy plane: about 27,000 m • Passenger jets: about 10,000 m • Mt. Everest: 8,850 m  • Denali/McKinley: 6,194 m  • Salt Lake City: 1,300 m  • Chicago: 204 m  • Florida's highest point: 105 m  • Death Valley: 86 m  • Dead Sea: 411 m 

35. Astronomical Measurements • Most of these measurements are just FYI—I wouldn't expect the average citizen to know many of these. An exception would be the Earth-Sun distance or the Earth's circumference. • Earth-Sun distance: 150,000,000 km  • Earth-Moon distance: 385,000 km  • Earth circumference: 40,000 km  • Geostationary orbit: 35,786 km above surface of Earth • Earth radius: 6,370 km  • Moon radius: 1,737 km  • Low Earth orbit: about 250 km above surface of Earth • U-2 Spy plane: 27 km above surface of Earth

36. The Conversion of the United States • There seems to be the general impression in the United States that the metric system was something that they tried years ago and it didn't stick. • It will always be an issue until we change. Metrication is inevitable as the world becomes more global and as the metric system becomes more and more entrenched in engineering, business, and everyday life in countries everywhere.

37. What Has Been Happening? • There was a push to convert the United States back in the 1970's. • Similar programs were quite successful in many countries (such as Australia), but in the United States the effort was largely derailed by a lack of commitment. • Since that time, metrication has been occurring at a slow pace. Many of our industries and corporations have been converting and often use metric. • These include the automotive industry, electronics companies, and companies such as Kodak. • Most recently, consumer products have started appearing in metric sizes (such as some shampoo, mouthwash, bottled drinks, etc.). • Over the past few decades, while we have been making slow progress in conversion, other countries around the world have been developing their economies and solidifying their use of the metric system.

38. Where Are We Now? • The attitude of many in America has been that others should just deal with our measurement system. • However, 95% of the world now lives in countries that are entirely or mostly metric. • Worldwide use of the metric system has solidified even during America's reign as superpower. • We simply are not able to impose our system on the rest of the world. Many other countries are recognizing this and they are taking steps to enforce metric usage in trade because metric units are the accepted international standards. • Many of our trading partners require or soon will require all imports of commodities to be labeled in metric units only.

39. Where Are We Now? • For example, it is against the law for a company to import a soft-drink bottle into Korea if it is labeled "20 FL OZ (591 mL)". • It would be filled to 600 mL and be labeled in milliliters, no ounces allowed. • Similar laws will apply in the European Union within a few years. Thus, a global soft-drink manufacturer needs two different product lines (with different product sizes) to maintain the U.S. measures in the United States. • Some trade groups have complained that these laws are protectionist measures, but they simply require that the accepted standards be followed. • U.S. companies are not penalized if they just comply. For this reason, many large U.S. companies have already converted their products to metric sizes, and many more will do so in the near future.

40. What Happens Next? • In order to help our companies produce goods for a world market, some are suggesting that we change U.S. law to allow metric-only labels on consumer goods. • This means that customers will be seeing more and more metric when they go to the grocery store. • In 2005, proposed legislation to allow metric-only labeling was going to be submitted to Congress, but it was not, primarily because of opposition from the Food Marketing Institute. • It is not clear what will happen next, but the European Union was given assurance in 1999 that the legislation would be passed by 2010 so that we can stop inflicting our units of measure on them in international trade. • Keep an eye out for more metrics popping up in your life!

41. The Metric “T” Can you figure out the meaning of these?: • kg • mm • daL • mg • cm • kg

42. 1 2 3 MetersLitersGrams How do you use the “ladder” method? 1st – Determine your starting point. 2nd – Count the “jumps” to your ending point. 3rd – Move the decimal the same number of jumps in the same direction. Starting Point Ending Point __. __. __. 2 3 1 Ladder Method KILO1000Units HECTO100Units DEKA10Units DECI0.1Unit CENTI0.01Unit MILLI0.001Unit This should go in Journal Entry #1 4 km = _________ m How many jumps does it take? 4. = 4000 m

43. Compare using <, >, or =. 56 cm 6 m 7 g 698 mg Conversion Practice Try these conversions using the ladder method. 1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm 14 km = _______ m 109 g = _______ kg 250 m = _______ km

44. Metric Conversion Challenge Write the correct abbreviation for each metric unit. 1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____ 2) Meter _____ 5) Millimeter _____ 8) Centimeter _____ 3) Gram _____ 6) Liter _____ 9) Milligram _____ Try these conversions, using the ladder method. 10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm 11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km 12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg 13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm 14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g kg mL km m mm cm g L mg 5000 160 2 .198 2.5 104,000 .075 4.8 65,000 .5 63 5600 .8 560 .12

45. Compare using <, >, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L 26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm < < = = < <