Real Numbers Are Real Easy

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Real Numbers Are Real Easy!

• A user-friendly guide.

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Table Of Contents

• What Are Real Numbers? 5
• How To Add Real Numbers 6
• How To Subtract Real Numbers 7
• Mini Quiz 1 8
• Answers to Mini Quiz 1 9
• How to Multiply/Divide Real 10 Numbers

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Table Of Contents

• Mini Quiz 2 11
• Answers to Mini Quiz 2 12
• The Number Line 13
• Absolute Value 14
• Absolute Value (.continued) 15
• Mini Quiz 3 16

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Table Of Contents

• Answers to Mini Quiz 3 17
• Cool Math Links 18

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• What Are Real Numbers?

• Real Numbers are basically all positive and
  negative numbers, along with zero in the middle
  to separate them.
• They are what people see most of the time on
  number lines.
• They go on forever in either direction.
• Contrary to what some may say, there are no such
  things as fake numbers.

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How To Add Real Numbers

• Adding Real Numbers is just like thinking about
  having and owing money.
• A - next to a number means thats how much
  money is owed.
• If there is no -, or if you see a next to a
  number, that is money you have.
• Take a problem two numbers at a time, going from
  left to right. The answer will either be that
  you still have money, still owe money, or you no
  longer have any money left because you broke
  even.
• Visit http//www.mathdork.com for great examples!

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How To Subtract Real Numbers

• Subtracting Real Numbers starts with knowing how
  to read negatives (-).
• - signs are sign-changers. They will change
  whatever they touch into its opposite. They are
  read as, The opposite of.
• For example, -(-5) can be read as the opposite
  of negative five, which is 5.
• In one like -3-(-4), you would first need to get
  the opposite of -4 which would be -34, then
  think of money to find the answer. If you said
  its 1, you are right!

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Mini Quiz 1

• Lets see how much youve picked up so far
• 1) -39 ?
• 2) -25 10 ?
• 3) -34 15 ?
• 4) 20 (-12) ?
• 5) -5 (-5) ?

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Answers

• Lets see how good you did
• 1) -39 6
• 2) -25 10 -15
• 3) -34 15 -49
• 4) 20 (-12) 32
• 5) -5 (-5) 0

I cant believe this stuff used to give me a hard
time before.
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How To Multiply and Divide Real Numbers

• The rules for these operations are simple and
  few
• Two same signs -Example -3(-5) 15
• -Example -100/-10 10
• Two different signs -
• -Example 10(-3) -30
• -Example -20/5 -4
• Whats important to remember is to always take
  two numbers at a time, and youll be fine!

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Mini quiz 2

• Lets see how much youve learned about
  multiplying and dividing real numbers!
• 1) -5(-8) ?
• 2) -32/8 ?
• 3) -12(2) ?
• 4) -40/-20 ?

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Answers

• Lets see how good you did
• 1) -5(-8) 40
• 2) -32/8 -4
• 3) -12(2) -24
• 4) -40/-20 2

When was the last time you remember being this
happy about taking a quiz?
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The Number Line

• A number line contains all the Real Numbers there
  are.
• It never ends. It runs forever in both the
  positive and negative directions.
• Zero sits right in the middle, and separates
  positives from negatives.
• It looks something like this

• Notice the arrows at the two ends of the line.
  They are telling you that each side runs on
  forever.

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Absolute Value

• How far out a number is on a number line can be
  determined by how far it is in jumps from zero.
  
• The Absolute Value of a Real Number tells how
  many jumps that is. Take a look below

More
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Absolute Value (.continued)

• The symbol for Absolute Value are two straight
  vertical lines, like this a
• The a is a variable and can be any Real Number,
  like this -5. Here, this is asking, How far
  is -5 from zero? If you said 5 jumps, you are
  right! So the answer is -5 5.
• Sometimes, youll already have an answer and want
  to work backwards to find out what number was
  inside the Absolute Value to give that to you.
• For example, if you get a 10, youre being
  asked to say what Real Number value(s) a could
  be so that it is exactly 10 jumps from zero.
  Since 10 and -10 each fit this description, they
  are both the right answer. So a10 and also
  a-10.

(Click on the image to start.) This example is
based on the same idea in the second highlighted
paragraph.
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Mini Quiz 3

• This is your final quiz! Hope you do well!?
• 1) 2 ?
• 2) -5 ?
• 3) m 4 m ?
• 4) c 7 c ?
• Bonus(1pt.) --10 ?

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Answers

• Lets see how good you did
• 1) 2 2
• 2) -5 5
• 3) m 4 or m -4
• 4) c 7 or c -7
• Bonus --10 -10

Does your expression look Like hers? If so,
then..Congradulations!!
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Cool Math Links

• Just about anything having to do with math
  http//www.math.com
• If you are into fractals, then try
  http//math.youngzones.org/Fractal20Gallery/index
  .html
• A small hoard of great site links is at
  http//www2.fultonschools.org/teacher/ogan/games_t
  hat_help_to_build_basic_s.htm
• Just ask Dr. Math at http//mathforum.org/library
  /drmath/sets/mid_factoring.html
• This site has an archive of stuff
  http//archives.math.utk.edu/cgi-bin/interactive.h
  tml
• Tutoring, math comics, and other humor
  http//www.homestead.com/stroh/mathpage.html
• MS Encarta has an awesome site on tutorials
  http//encarta.msn.com/encnet/homework/math.aspx
• Math video clips galore! Check them out!
  http//www.kyrene.org/schools/brisas/sunda/math/ma
  th_clips.htm

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