1. The Metric System & Unit Conversions: aka Dimensional Analysis

2. The Metric System In America, we use the standard system of units
(pounds, ounces, miles, feet, etc)
In Science, and in all other countries, a different system is used called the metric system.
Fill in 1st and 2nd blanks in the notes

3. The Metric System U.S. is the ONLY major nation not using it.
The U.S. will probably switch to it in your lifetimes because:
U.S. is the ONLY major nation not using it.
Easier trade and communication
It is a decimal system (like our money) and much easier to use.

4. Metric VS Standard Neither is more ACCURATE, just different.
Fill in 3rd blank in notes.

5. Standard System 88 different types of units hundreds of conversions.
Even most Americans can’t name more than a dozen
hundreds of conversions.
Most American citizens know very few.
Fill in the 2 boxes under the title STANDARD in the notes.

6. Metric System Only 7 base units 10 common prefixes (20 total)
Second s time
kilogram kg mass
° kelvin K temperature
meter m distance
candle c light
ampere A current and resistance
mole mol amount of substance
10 common prefixes (20 total)
Only one set of conversions to learn. The one set works for everything.
Fill in the two boxes labeled METRIC in the notes.

7. Most Common Metric Base Units
Length
Meters (m)
Mass – (weight)
Grams (g)
Volume
Liters (L)
As each of the three base units fill in, do the appropriate PRACTICE question in the notes as a class.

8. That make the base unit BIGGER
Metric Prefixes
That make the base unit BIGGER

9. Meaning (multiply by):
Prefix:
Symbol
S. N.
Meaning (multiply by):
Yotta- Y
1024
Zetta- Z
1021
Exa- E
1018
Peta- P
1015
Tera- T
1012
Giga- G
109
Mega- M
106
kilo- k
103
1000
hecto- h
102
100
deka- da 10
Have the students fill in the SYMBOL and SCIENTIFIC NOTATION in their notes. Have them fill in the SN with the format 1x1024, etc.

10. That make the base unit SMALLER
Metric Prefixes
That make the base unit SMALLER

11. deci- d 10-1 0.1 centi- c 10-2 0.01 milli- m 10-3 0.001 micro- µ (mu)
Prefix:
Symbol
S. N.
Meaning (Multiply by)
deci- d
10-1
0.1
centi- c
10-2
0.01
milli- m
10-3
0.001
micro-
µ (mu)
10-6
nano- n
10-9
pico- p
10-12
femto- f
10-15
atto- a
10-18
zepto- z
10-21
yocto- y
10-24
Have the students fill in the SYMBOL and SCIENTIFIC NOTATION in their notes. Have them fill in the SN with the format 1x1024, etc.

12. Unit Conversions 180 minutes!
How many minutes are in 3 hours?
180 minutes!
Many of you knew this already or can do it in your head, instinctively.
To get the answer, you needed two things:
CONVERSION FACTOR (60 min = 1 hour.)
Know to DIVIDE or MULTIPLY.
Class discussion.

13. Unit Conversions
How about a harder one? How many minutes are in hours?
Since you can’t do this in your head, you must think and use the same method you used before.
We will use a system called the factor-label method, or Dimensional Analysis.
minutes
Work this problem very quickly on the board to show the students the dimensional analysis process.

14. Dimensional Analysis – Step 1
Convert 14.3 cm to meters:
______|________ l
Write your t-chart.
No blanks in notes, just have students watch & learn this problem.

15. Dimensional Analysis – Step 2
Convert 14.3 cm to meters:
14.3 cm |________ l
Add the given with its label.
(IE – the number the problem gives you and its UNIT)

16. Dimensional Analysis – Step 3
Convert 14.3 cm to meters:
14.3 cm |________
l cm
Add the units of the given on the t-chart.
It will go DIAGONALLY from the original.
This is so the units will cancel out later.

17. Dimensional Analysis – Step 4
Convert 14.3 cm to meters:
14.3 cm |______m_
l cm
Add the unit you are trying to get to.

18. Dimensional Analysis Convert 14.3 cm to meters: 14.3 cm |___1 ___m_
l cm
Fill in the conversion factor that links the two units.
EX: 1 m = 100 cm
(you will usually need to look this up.)

19. Dimensional Analysis Convert 14.3 cm to meters:
cm- |___1 ___m_ =
l cm-
Cancel units and do the math.
MATH:
Multiply if the number is on the top
Divide if the number is on the bottom
x 1 ÷ = m

20. How to Solve a Dimensional Analysis Problem
Your notes have a fully worked example problem.
We will go over it now.
Note the location of this page.
Use it as a reference for future problems.
Go over the example problem in the notes.

22. Temperature : K vs °C vs °F
kelvins
degrees celsius
degrees fahrenheit
symbol °K °C °F
boiling point of water
373.15
100.
212.
average human body temperature
37.
98.6
average room temperature
20. to 25.
68. to 77.
freezing point of water
273.15 0.
32.
absolute zero

23. Temperature Conversions
°C & K are the metric units for temp.
[K] = [°C] + 273.15
°F is the standard unit for temp.
To convert between °C and °F: OR