1. Observation in Science

2. Qualitative Observations
Describe characteristics or “qualities”
Determined with senses
or determined with instruments
Ex. Microscope to see things that are really small
Radio Waves
(High frequency vs. actual frequency, measured in Hertz)
Can be easy to make
Can be unreliable
Illusions

4. Quantitative Observations
Counting or Measuring
Must include a Number and a Unit
Require some measuring instrument
Must be Standardized
compare the cubits:

5. Some Ancient Measurements
Hand - width of a hand
Foot - length of a foot
Fathom - width of outstretched arms
Furlong - length of a furrow
Inch grains of barley or a thumb width
Mile paces
All have since been standardized
Why do you think that is so?

6. Standardized Measuring Systems
English System
SI (Metric) System
Both are Precise and Accurate

7. English System Advantages: Familiar Uses Fractions easy to divide
things up

8. English System Disadvantages Fractions
Quick… what is 3 7/ /32 ?
Cannot be entered into most calculators
8 25/32

9. English System Disadvantages Conversions How many….
Inches in a foot? Feet in a yard? Feet in a mile?
Ounces in a cup? Cups in a pint? Pints in a gallon?
Ounces in a pound? Pounds in a ton?
Firkins in a barrel? Scruples in a drachma? 8
5280 12 3 4 16
2000 2

10. English System Disadvantages Used in few areas
Myanmar
Liberia
Where the English System is still (sometimes) used

11. The SI (metric) System Advantages Decimals
Quick… what is ?
Easily entered into a calculator
8.78

12. The SI (metric) System Advantages Conversions
All conversions are by multiples of 10
10 centimeters in a decimeter
10 decimeters in a meter
10 meters in a Dekameter
10 Dekameters in a Hectameter

13. The SI (metric) System Advantages It is International
Used more commonly in US now:
Fat in foods
Swimming and running races (“Fun runs”)
Beverages
etc…

14. The SI (metric) System Disadvantages of SI system (right now)
Less familiar to us