1. Units of Measurement
Science 9
September 2016

2. Vocab
Unit – a standard of measurement in which other measurements are expressed.
English System (United States Customary System) – system of measurement used in the US, includes inches, gallons, pounds, miles, etc.
Metric System – system of measurement used in countries other than the US and by the scientific community; units are organized by factors of 10.
Prefix – element placed at the beginning of a word that changes the meaning of the word; in the metric system, it indicates a unit smaller of larger than the basic unit by factors of 10.

3. Why is measurement important?
Use it in daily life
Cooking
Construction
Decorating a room
Driving
Communication
Need to be able to communicate measurements and distances to other people

4. Measurement & Physics
Physicists try to find relationships between the quantities they measure  use units of measurement to do this
Measure the very largest and smallest things in the universe
Smallest: mass of an electron = yg
Largest: light years (distances between stars and galaxies

5. Units of Measurement Distance Mass Time Area/Volume Temperature inch
milligram
hours
in^2, in^3
Fahrenheit
meter
ounces
seconds
m^2, m^3
Celsius
mile
pounds
days
Liters
Kelvin
feet
gram
months
Gallon
centimeter
kilogram
years
Quart
millimeter
tons
minutes
Pint

6. How to use a ruler:
1. Determine if you are measuring in centimeters or inches and find that unit’s side of the ruler.
centimeters
inches

7. How to use a ruler “0” mark
Place the “0” mark at one end of the object you are measuring.
“0” mark

8. How to Use a Ruler
Record the ruler marking that falls at the other end of the object
For INCHES:
- Each dash after a whole inch is 1/16 of an inch
For CENTIMETERS:
- Each dash after a whole centimeter is 1/10 of a centimeter

9. Measurement Lab

10. Relative Size Unit Relative Size Examples Inches 1 in
Photo size, body parts
Feet
1 ft = 12 in
Height of people, room size
Yard
1 yd= 3 ft
Football field
Meters
1 m ~ 1 yd
Height of people, track length
Kilometers
1km = 1000m
Car travels, between cities
Centimeters
1 cm = 0.01 m
Paper, small machine parts, body parts
Millimeters
1 mm = m
Coins

11. Two Main Systems of Measurement
United States Customary System (USCS)
System International (SI)- Metric System

12. USCS Used in the U.S. and Burma
Distance: inch (in), foot (ft), yard (yd), mile (mi)
Mass: pound (lb)
Time: second (sec)
Temperature: degrees Fahrenheit (F)

13. Metric System Used by all other countries and the scientific community
Units that are larger or smaller units than the basic units are defined in multiples of 10
Basic Units
Distance: meter (m)
Mass: gram (g)
Time: second (s)
Temperature: degrees Celsius
Volume: Litre (L)

14. Start here with metric conversion pre-test

15. Metric System: Prefixes
Adding a prefix to a basic metric unit increases or decreases the unit size by a factor of 10
Prefixes are always added to the beginning of Metric basic units
For example,
centimeter (cm)
milliliter (ml)
kilogram (kg)

16. Metric Prefixes Prefix Symbol Relation to Basic Unit milli- m
1000 mm = 1 m
centi- c
100 cm = 1 m
deci- d
10 dm = 1 m
deka- da
1 dam = 10 m
hecto- h
1 hm = 100m
kilo- k
1 km = 1000 m

17. Conversion Hints
Staircase Method

18. Rules to using the Staircase Method of conversion
Find the unit on the staircase where you are STARTING.
ex. Convert 5 m = ________ cm
You are starting at m.
2. Count up or down the stairs ending on the unit you need to convert to.
ex. 5 m = ________ cm
You need to convert to cm.

19. 3. If you counted UP the stairs, move the decimal point LEFT. 4
3. If you counted UP the stairs, move the decimal point LEFT. 4. If you counted DOWN the stairs, move the decimal point RIGHT. ex. 5 m = ________ cm

20. 5 m = ______ cm Move decimal 2 places to the right. 5 m = 500 cm

21. Convert: 116 kg = _______________ g
Start at “kilo” and find “gram” (base).
Count steps down…3
Move decimal 3 spots to the right
116 kg = 116,000 g

22. Convert: 5.468 hL = ____________ cL Start at “hecto” and find “centi”
Count steps from h to c = 4 down
Move decimal 4 spots to the right
5.468 hL = 54,680 cL

23. Convert: 9,436 mm = _____________ m
Start at “milli” and find “meter” (base)
Count steps from m to M = 3 steps up
Move decimal 3 spots to the left
9,436 mm = m

24. Now, do the pre-test again knowing the staircase method of conversions.

25. PRACTICE!! You will get a sheet to practice conversions.
Use the staircase method (it is the easiest!)
Do not be afraid to ask for help.