1. 1.6 Scientific Measurement

2. History of Measurement
The metric system was developed in 1668 and adopted by France in 1799 and from 1800 to became the worlds dominant measuring system.
Some countries still use customary units (The U.S. is one)
7 base units all based on a standard

3. Quotes of Measurement
“Not everything that counts can be counted and not everything that can be counted counts.”
Albert Einstein

4. When do we measure?
Measurement takes place during the: “____________________” phase of the scientific method
Collect & record data

5. SI Units
The International System of Units – the set of measuring units that scientists use.

6. Base Units
The most basic units of SI measurement are base units. The SI Base units are:
Length: Meter – m
Mass: Kilogram – kg
Temperature: Kelvin – K
Time: Second – s
Amount of a Substance: Mole – mol
Electric Current: Ampere – A
Luminous Intensity: Candela - cd

7. Derived Units Combinations of base units There are more…..
Area: Square meter – m2
Volume: Cubic meter – m3
Density: Kilograms per cubic meter – kg/m3
Pressure: Pascal's (kg/ms2) – Pa
There are more…..

8. Metric Prefixes Kilo Hecta Deka (Meters, liters, or grams) Deci Centi
Milli
Kangaroos Hopping Down Mountains Drinking Chocolate Milk!!!

9. Drawing the Metric Prefix Line!
Prefix Symbol Decimal Value Power of 10
kilo k 1,
hecta h
deka da
BASE
deci d
centi c
milli m

10. How many jumps does it take?
Ladder Method 1 2 3
KILO 1000 Units
HECTO 100 Units
DEKA 10 Units
DECI 0.1 Unit
Meters Liters Grams
CENTI 0.01 Unit
MILLI Unit
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.
4 km = _________ m
Starting Point
Ending Point
How many jumps does it take? 4. 1
__. 2
__. 3
__.
= 4000 m

11. Conversion Practice
Try these conversions using the ladder method: 1
1000
1000 mg = _______ g 1 L = _______ mL
160 cm = _______ mm 14 km = _______ m
109 g = _______ kg m = _______ km
1600
14000
.109
.250

12. Practice Problems 200 20 km = _______ hm .045 daL = _______ mL
1000 mm = _______ m = _________ cm
450 1
100

13. Base Units length Meter measures _________. Grams measure __________.
Liters measure ___________.
mass
volume

14. Precision vs. Accuracy
Precision – how exact a measurement is, how repeatable something is.
Accuracy – the closeness of the measurement of the actual value, how close you are to the goal
Dart Throwing Analogy

15. Neither accurate nor precise Precise but not accurate
Accurate or Precise?
Goal: To throw a dart and hit the bulls-eye (red circle)
Neither accurate nor precise
Precise but not accurate
Precise AND accurate