Understanding Numbers

1
Understanding Numbers

• Alex Smart
• Goody Twoshus
• S'Marty Pants

2
Numbers fall into two categories

• Real Numbers
• Rational numbers
•  
• Natural numbers
• Whole numbers
• Integers
• Irrational numbers

• Imaginary
•  
• The letter "i" represents imaginary numbers
• square roots of negative numbers
• even roots of negative numbers

3
Real Numbers are made of two types of numbers

• Rational Numbers
• can be expressed as a fraction
• Can be non-terminating
• Does repeat decimal numbers

• Irrational Numbers
• Cannot be expressed as a fraction
• Non-terminating, non-repeating decimal

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Examples of rational and irrational numbers

• Rational
• 1/2    1/3    1/2345  4
•  
• perfect square roots
•  
• perfect cube roots
•  
• perfect any roots 

• Irrational numbers
• The most famous is pi
• Any non-perfect square root
• Any non-perfect any root

5
Natural numbers

• What is taught the first time you count? 1, 2, 3,
  4, 5, 6...
• Also referred to as counting numbers
• Start at 1 and go to forever or infinity....

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Whole Numbers

• Whole numbers are natural numbers and zero....
• Zero (0) looks like a hole.....(w)hole
  numbers....
• Whole numbers depict quantities in wholes....no
  wholes (0) or many wholes....(1, 2, 3, 4...)

7
Integers

• You have 3 whole loaves of breads.....
• What happens if you destroy 5 whole loaves of
  breads of your neighbor?
• You give your 3 and now you owe 2 to your
  neighbor
• Integer numbers are used to show what you owe
• Instead of owing 2 loaves, you have -2
  loaves.....
• Integers are mirror images of whole
  numbers....like opposites

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Rational Numbers

• What about if you have 3 loaves and the fourth
  loaf is split with your brother?
• You have more than 3 and less than 4 you have 3
  and a half.....
• The 3 and a half is a rational number.....
• Rational numbers are natural numbers, whole
  numbers, integers and the parts between those
  numbers
• Represented by deciamals and fractions
• Decimals that repeat are rational also

9
Irrational Numbers

• AKA crazy numbers....hence irrational number
• These numbers cannot be written as a
  fraction...the decimal number goes on forever,
  never repeating itself