1. Putting Numbers in Perspective
Chapter 2, Unit B
Putting Numbers in Perspective

2. Essential Questions
What situations do you see numbers that are really large or really small?
What are some techniques we can use to put these numbers in perspective to gain meaning?

3. Scientific Notation
Numbers between 1 to 10, multiplied by a power of 10
Change to Scientific Notation:
move the decimal point to after the first non-zero digit
The exponent is the number of times you moved left (+) or right(-)
Change from Scientific Notation:
Power of 10 tells you how many times to move the decimal right (+) or left (-)
If decimal point creates any open places, fill with zeros

4. Practice: Change from Scientific Notation:
8x10^-2
5x10^3
9.6x10^4
2x10^-3
3.3x10^-5
7.66x10^-2
Change to Scientific Notation:
4327
904.35
0.0045
624.87
0.1357

5. Approximations with Scientific Notation
Multiplication/Division
Multiply or divide the #
Add (x) or subtract (/) the exponents
Check to see if answer is in scientific notation
Addition/Subtraction
Change the numbers from scientific notation
add or subtract
Change the answer to scientific notation

6. Approximations with Scientific Notation
(4x10^7) x (2x10^8)
(3.2x10^5) x (2x10^4)
(4x10^3) + (5x10^2)
(9x10^13)/(3x10^10)

7. Order of Magnitude Estimates that only give a broad range of values
Sounds like: “the population of the US is ‘on the order of 300 million’” which means it is nearer to 300 million than 200 million or 400 million
When you would use it:
Age in hours
Number of breaths you take in a year
Number of heartbeats in a lifetime
How much we spend on ice cream in a year
Amount of oil the US uses in a year

8. Your favorite… conversions!
Tips to remember:
To “cancel” a label it must be in the opposite location
The final answer label must be in the numerator
PRACTICE:
Seconds in a day
Hours in a year
If you are going 50 mph, how many feet per second are you traveling

9. HOMEWORK: Calendar Adjustment
D28: pp
#15, 17, 19, 21, 23, 25, 27,