Fractions

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Fractions

• Day 4

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Fractions

• Numbers such as ½ and -¾ are called fractions.
• The number above the fraction line is called the
  numerator.
• The number below the fraction line is called the
  denominator.

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Reducing Fractions

• When both the numerator and denominator have a
  common divisor, we can reduce the fraction to its
  lowest terms.
• A fraction is said to be in its lowest terms (or
  reduced) when the numerator and denominator are
  relatively prime (have no common divisors other
  than 1).

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• To reduce a fraction to its lowest terms, divide
  both the numerator and the denominator by the
  GCD.
• The fraction 6/10 is reduced to its lowest terms
  as follows.

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You Try

• Reduce to its lowest terms

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Mixed Numbers and Improper Fractions

• The number 2¾ is an example of a mixed number.
  It is called a mixed number because it is made up
  of an integer and a fraction.
• 2¾ means 2 ¾
• An improper fraction is a fraction whose
  numerator is greater than its denominator.

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The figure shows improper fractions and mixed
numbers.
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How do you convert mixed numbers to improper
fractions?
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Example Convert to Improper Fractions.
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How do you convert improper fractions to mixed
numbers?
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Example Convert to a mixed number.
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Example Convert to a mixed number.
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Multiplication of Fractions

• Multiply the numerators and multiply the
  denominators together then reduce if necessary.

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Examples
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Reciprocal

• The reciprocal of any number is 1 divided by that
  number.
• The product of a number and its reciprocal must
  equal 1.

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Division of Fractions

• To find the quotient of two fractions, multiply
  the first fraction by the reciprocal of the
  second fraction.

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Addition and Subtraction of Fractions

• Before we can add or subtract fractions, the
  fractions must have a lowest common denominator.

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Example Evaluate
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Adding or Subtracting Fractions with Unlike
Denominators

• Use prime factorization to find the LCD for the
  denominator.
• Example

LCD
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Addition Example
Now Reduce!