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					                    measurement
   -a way to describe the world with numbers
   Answers questions: how much? How long? How far?
   Describe the amount; cost; distance; volume; mass; how fast; age
   Information described with numbers




                          Chapter 2 Vocabulary/Notes
              Estimation
• Helps you make a rough measurement of
  an object by guessing
• Based on experience
• Useful when you are in a hurry and exact
  data is NOT required
• Improve with experience, practice, and
  understanding

               Chapter 2 Vocabulary/Notes
           Using Estimation

• You can compare an object whose length
  you don’t know to familiar objects
• Often use the word “about”
• Also used to check that an answer is
  reasonable
• 1 m = about height of a door knob above the
        floor
• 1 cm = about the width of your smallest finger
• 1 mm = about the thickness of a dime

                  Chapter 2 Vocabulary/Notes
              Precision
• Describes how carefully you make your
  measurement
• The tool used determines the precision of
  the measurement
• The more improved the tool the more
  précised the measurement
• Can be reproduced or copied

                Chapter 2 Vocabulary/Notes
              accuracy
• Compares a measurement to the real
  value
• The more accurate the measure, the
  closer it is to the true value




              Chapter 2 Vocabulary/Notes
                Steps in Rounding
• Not all measurements must be measured with great
  precision

• 1. Look at the digit to the right of the place being
  rounded
   – The digit remains the same if the digit to the right is 0, 1, 2, 3, or 4
   – Round up if the digit to the right is 5, 6, 7, 8, or 9



   2. The remaining digits to the right of the rounding place
      are eliminated from the rounded answer if it is a
      decimal

                             Chapter 2 Vocabulary/Notes
                               SI
•   Means International System of Units
•   Established in 1960
•   General system for measurement
•   To avoid confusion, scientists use this common
    language
•   Worldwide standard of physical measurement for
    industry, science, and commerce
•   Uses units such as meters, cubic meter, grams, and
    Kelvin
•   Uses multiples of 10
•   To convert between units you multiply or divide by
    powers of 10

                      Chapter 2 Vocabulary/Notes
                   length
• Distance between two points
• Use the meter unit to measure




               Chapter 2 Vocabulary/Notes
                     volume
• Amount of space an object occupies
• Cubic meter (cm3) is used
• Formula: Volume=length x width x height
  or           V = l x w x h or V = (l)(w)(h)
• Liquid volume is measured using liter
     • 1 cm3 = 1 mm of water




                   Chapter 2 Vocabulary/Notes
                         mass
• Measures the amount of matter in an object
• Uses kilogram unit
• 1 L of water = 1 kg
• Use a pan balance to measure
• Pan balance compares an object to a known mass; it is
  balanced when the masses on both sides are equal
• Depends on the amount of matter in an object
• NEVER changes

• Mass and weight ARE NOT the same


                    Chapter 2 Vocabulary/Notes
                 Weight
• Measurement of force
• Depends on gravity
• Can change depending on where the
  object is located
• Spring scale measures weight; the reading
  on the scale depends on the force pulling
  the spring

               Chapter 2 Vocabulary/Notes
                 temperature
•   Measures how hot or cold an object is
•   In SI it is measured with the Kelvin (K) scale
•   Measured also in Fahrenheit or Celsius
•   273 K = 0°C = 32°F (freezing point of water)
•   373 K = 100°C = 212°F (boiling point of water)
•   Zero Kelvin is the coldest temperature possible
    in nature



                    Chapter 2 Vocabulary/Notes
                    Time
• interval between two events
• Measured in seconds (s) or hours (h)




               Chapter 2 Vocabulary/Notes
                     rates
• A ratio of two measurements with different
  units
• Example: speed-distance traveled in a
  given time
• Measured in kilometers per hour (km/h)
• Are combinations of units
     Examples: grains/liter; °C/hour

                Chapter 2 Vocabulary/Notes
            photographs
• Shows an object exactly as it is
• Movie show can be slowed down or
  speeded up




              Chapter 2 Vocabulary/Notes
               drawings
• Can show important things and leave out
  unimportant details
• Illustrations
• Can show things we can’t photograph
• Can show hidden things
• sketches


               Chapter 2 Vocabulary/Notes
                  Tables
• Organized way to collect and display data
• Displays info in rows and columns so it’s
  easier to understand




               Chapter 2 Vocabulary/Notes
                 graphs
• Show the relationships between the data
• Used to collect, organize and summarize
  data in a visual way
• Can display one set of data or more
• Three common types:
     -line graphs
     -bar graphs
     -circle graphs
               Chapter 2 Vocabulary/Notes
                 Line graph
• Has two variable (something that can change or
  vary)
• Used to show the relationship between
  two variables
• Both variables must be numbers
• Has a vertical axis and a horizontal axis
  (bottom line)


                  Chapter 2 Vocabulary/Notes
              Bar Graph
• Uses bars to show the relationships
  between variables
• One variable MUST be a number; the
  other variable is divided into parts




               Chapter 2 Vocabulary/Notes
               Circle Graph
•   Shows the parts of a whole
•   The circle represents the whole
•   Sections represents the parts
•   All the sections together equal 100 percent




                  Chapter 2 Vocabulary/Notes
         Misleading Graphs
• The way you mark the scale on a graph
  can create the wrong impression
• A broken scale (on the vertical axis) is
  used for small but significant changes




                Chapter 2 Vocabulary/Notes

				
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