process versus the reason why 1.because subtraction means to take away 2.because multiplication and...
TRANSCRIPT
Process versus The Reason Why
1. Because Subtraction Means to Take Away
2. Because Multiplication and Division of Integers Follow a Pattern
3. Because it Makes Sense
Because Subtraction Means to
Take Away
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What is 5 – (-6) ?+
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The Answer is 11.
What is 3 - 6 ?+
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The Answer is -3.
Because Multiplication and Division
of Integers F
ollow a Pattern
Why does a positive times a negative equal a negative?
4 • 3 = 124 • 2 = 8 4 • 1 = 44 • 0 = 0
4 • -1 = ?Look at th
e patternThe Answer is -4.
So a positive times a negative is a negative.
But why does a negative times a negative equal a positive?
-4 • 3 = -12-4 • 2 = -8 -4 • 1 = -4-4 • 0 = 0
-4 • -1 = ?
Look at the pattern
The Answer is 4.
So a negative times a negative is a positive.
Well, knowing a positive times a negative is a negative, also means that a negative times a positive is a negative, so again…
Because It Makes Sense
Floors on Elevators
This is an elevator panel with NEGATIVE numbers.
How far many floors have you gone up if you start at the lowest floor and go to the highest floor?
(1)Set up the expression(2)Explain your reasoning(3)Solve the problem
Answer: 17-(-2) = 19 floors
The World’s Tallest Building
http://img.dailymail.co.uk/i/pix/2007/07_02/WorldsTallestDM_468x525.jpg
How much taller is The Burj Dubai compared to The Empire State Building?
Answer: 512 – 381 = 131 meters
The U.S. National Debt
U.S. NATIONAL DEBT CLOCK The Outstanding Public Debt as of 09 Jan 2010 at 01:30:59 PM GMT
is:
http://www.brillig.com/debt_clock/
If the government taxed each American $40, 068.00, approximately how many Americans would it require to pay to off our National Debt?
Answer: -12,287,322,881,897 ÷ -40,068.00 ≈ 306,666,778 Americans
Why Do I Need to Know This?(Motivation and Real World Applications)
http://www.labsafety.com/images/xl/Weather-Thermometer-40-to-LSS_i_LBM37561Z.jpg
What is the difference between the lowest and the highest temperature reading on the thermometer?
Answer: 120 – (-40) = 160°F
Above and Below Sea Level
http://www.treehugger.com/mariana%20trench.jpg
http://www.thetravelpeach.com/asia-vacations/everest-mount.jpg
Mariana Trent-10,916
Mount Everest29,035
What is the difference between the highest point above sea level and the lowest point below sea level?
Answer: 29,035 – (-10,916) = 39,951