 Created during French Revolution › in 1790‘s › 1793 French King Louis XVI beheaded › National Assembly of France sets up new government › French Academy of Science told to design new system of weights and measures › Lavaiosie appointed to head committee

 Called Systeme International d’Unitès, › or SI - International System of Units  Revised periodically › by International Bureau of Weight and Measures

 The English or Imperial System › a collection of functionally unrelated units  Difficult to convert from one unit to another  Ex. 1 ft = 12 inches = 0.33 yard = 1/5280 miles  Typical Units › length - inch, foot, yard, mile › weight/mass - ounce, pound › volume - teaspoon, cup, quart, gallon › temperature - degrees Fahrenheit › time - minutes, hours

 Universal - Used all around the world › Used in the scientific community and is the only accepted form of measurement › Used by the Olympics and International Sporting events. › Used by all industrialized nations  except United States  U.S. loses billions of dollars in trade

 Simple to use › A few base units make up all measurements  length - metre  mass - grams  volume - litres  temperature – degrees Celsius  time - seconds

 There is one standard unit of measurement for each type of quantity › To simplify things, very small and very large numbers are expressed as multiples of the base unit.  Prefixes are used to represent how much smaller or larger the quantity is compared to the base unit.  Easy to convert from one unit to another › shift decimal point right › shift decimal point left

 Same set of prefixes for all units › Greek - multiples of the base  kilo × the base  hecto × the base  deka - 10 × the base › Latin - fractions of the base  deci - tenths of the base  centi - hundredths of the base  milli - thousandths of the base  Mnemonic: “Kids Have Dropped Over Dead Converting Metrics.”

 Length - the distance between two points › standard unit is metre (m) › long distances are measured in km  Measured using a metre stick or ruler

 centimetre - cm › 1 m = 100 cm › 1 cm = 1/100th m  millimetr e- mm › 1 m = 1000 mm › 1 mm = 1/1000th m › 10 mm = 1 cm › measures very small lengths  kilometre - km › 1 km = 1000 m › 1 m = 1/1000th km › measures long distances

 Mass - the quantity of matter in an object › standard unit is gram (g)  Measured using a digital scale or triple beam balance

 Volume - the amount of space occupied by an object › standard unit is litre (L) › 1 L = 1000 ml = 1000 cm3 = 1 dm3 › Measured using a graduated cylinder  Capacity - a measure of the volume inside a container

› Litre - L  1 L = 1000 milliliters  1 L = 1000 cubic centimeters = 1000 cm3 › millilitre - mL  measures small volumes  1 mL = 1 cubic centimeter  1000 mL = 1 Liter  1 mL = 1/1000th liter › kilolitre - kL  measures large volumes  1 kL = 1000 L The SI unit for volume is NOT the litre, it is a Cubic metre. Litre are accepted as an SI derived unit.

 Measured with a graduated cylinder › Determine value of each mark on the scale › Read scale using the lowest position of the meniscus  Measure the meniscus at eye level from the center of the meniscus.  In the case of water and most liquids, the meniscus is concave. Mercury produces a convex meniscus.

 Displacement › Amount of water an object replaces › Equal to its volume

 Displacement - amount of water an object replaces › Procedure  Place graduate beaker beneath spout  Fill the overflow can with water until water begins to spill  Empty the excess water  Place object to be measured into the overflow can  Remove when water stops flowing out of the can  Measure the displaced water using a graduated cylinder.

Displacement Calculate the difference between the initial and final volume measurement.

 Volume - length x width x height › V = 2.8 cm x 3.2 cm x 2.5 cm › V = 22.4 cm3 › Measured with a ruler

 Density - a specific property of matter that is related to its mass divided by the volume. › D=M/V › the ratio of mass to volume  used to characterize a substance › each substance has a unique density  Units for density include:  g/mL  g/cm3  g/cc

 Time › metric unit is second (s)

 Temperature - the degree of “hotness” of an object › standard unit is celsius (°C) › measured with a thermometer

 Conversion Between Fahrenheit, Celsius, and Kelvin  Example: › Convert 75 ºC to ºF › Convert -10 ºF to ºC

 You can convert between units of measurement › within the metric system › between the English system and metric system

 You can convert between units of measurement › within the metric system › between the English system and metric system

 Let your units do the work for you by simply memorizing connections between units. › Example: How many donuts are in one dozen? › We say: “Twelve donuts in a dozen.” › Or: 12 donuts = 1 dozen donuts › What does any number divided by itself equal? › ONE!

 This fraction is called a unit factor › Multiplication by a unit factor does not change the amount - only the unit. › Example: How many donuts are in 3.5 dozen?  You can probably do this in your head but try it using the Factor-Label Method.

 Start with the given information…  Then set up your unit factor …  See that the original unit cancels out…  Then multiply and divide all numbers…

 Example: Convert 12 gallons to units of quarts.

 Example: Convert 4 ounces to kilograms.