 Before we had customary and metric units people measured various things with their body parts.  Examples: A. How many hands tall is the horse you are buying? B. One yard of fabric is the distance from your thumb to your nose.

 Finger- the width across your first finger  Hand- the width across your hand with your fingers together.  cubit- length of your arm from the end of your middle finger to your elbow

 Pace- length of a step or stride  Fathom- distance from fingertips of left hand to right hand with arms outstretched  Inch- distance from the tip of your thumb to the first knuckle.

 Yard- distance between thumb and nose with hand extended (stretched out)  Span- distance between the tips of the thumb and little finger with hand extended (spread apart)

 Measure the classroom objects and record on the class data table.

 Will each student’s measurements of classroom objects be the same?  Example: If we measure classroom objects with non-standard units, everyone will get the same answer.

ObjectUnitsMeasurement TextbookFingers TableHands ChairCubits Width of ClassroomPace Length of ClassroomFathom

 Was the class data the same as yours? Why or why not?  When might you use one of these units to take a measurement?  State one problem you found using these nonstandard units in measuring classroom objects.

Or for those of you who speak English… The international system

 This is the metric system  Every other country uses metric. The Unites States is one of the only nations that still uses the customary system. WHY do you think we don’t use the SI or metric system?

 For every metric unit, there is a base unit What you want to measure Unit you use LengthMeter MassGram VolumeLiter TimeSecond TemperatureCelsius

 A prefix is a part of a word that is added onto another word to make it have a new meaning  For the basic units there are prefixes to tell us how big or small they are  Example: pre-test, mis-spell, re-write

 If we want to decrease in size, we use milli- 1,000 times smaller  I like to think of Milli Mouse

 Then comes Centi- 100 times smaller  Think of Centi Cat

 Finally, there is Deci- 10 times smaller (pronounced De-see)  This is Deci Dog

 If we want to increase in size, we can use Deca- 10 times bigger  This is Deca Dolphin

 Next, we increase in size by 100- Hecto  This is Hecto Hippo

 Finally, we have Kilo- 1,000 times bigger  This is Kilophant

 Choose 3 of the following with your group and write them in your table: 1. Meter 2. Hand 3. Toothpick 4. Pencil 5. Person 6. Centimeter 7. Pace

 Which of these units is standard? Which are nonstandard?  Which units are metric?

 What pattern do you see? What do you infer?  How did your understanding of measurement units help you prove or disprove your prediction?  Discuss any problems that would explain unexpected results. Give suggestions for improving the activity.

 Write one or two sentences that state whether or not your data supported your prediction