Fractions
     
     
     
      Proper and improper fractions
      Mixed numbers
      Converting mixed numbers to improper fractions
      Converting improper fractions to mixed numbers
      Equivalent fractions
      Converting and reducing fractions
      Lowest terms
      Comparing fractions
      Decimal fractions
      Adding and subtracting like fractions
      Adding and subtracting fractions
      Multiplying fractions
      Reciprocal fractions
      Dividing fractions
      Simplifying complex fractions
Proper and improper fractions
A fraction is an expression representing a part, or several equal parts, of a unit. 
  Thus, for example in the fraction 3/4 the denominator 4 tells us how many parts  the whole is divided into, and the numerator 3 tells us how many of those parts we're dealing with.
When the numerator is less than the denominator, the fraction is proper, i.e. less than unity.
  When the numerator is greater than or equal to denominator, the fraction is improper, i.e. greater than unity:  
A fraction greater than 1 can also be written as a mixed number, i.e. as the sum of a positive integer and a proper fraction:
 Example:
   
Converting mixed numbers to improper fractions
To convert a mixed number to an improper fraction, multiply the whole number by the denominator of the fraction, add the numerator of the fraction to the product and write the sum over the given denominator.
Converting improper fractions to mixed numbers
To convert an improper fraction to a mixed number divide the fraction's numerator by its denominator. The integer part of the division is the integer part of the mixed number. The remainder of the division is the numerator of the resulting fraction, as is shown in the above example.
Converting and reducing fractions
Fractions that represent the same number are called equivalent fractions
For any fraction, multiplying the numerator and denominator by the same nonzero number gives an equivalent fraction.
A fraction is in lowest terms when the greatest common factor of its numerator and denominator is 1. 
To reduce a fraction to lowest terms, divide the numerator and denominator by their greatest common factor.
 Example:
 equivalent fractions:   and    
Comparing fractions
To compare fractions with the same denominator, look at their numerators. The larger fraction is the one with the larger numerator.
If the numerators of two fractions are the same, the fraction with the smaller denominator is the larger fraction.
 Example:  To compare fractions with different denominators, e.g. 4/5 and 7/9, multiply the numerator 
and the denominator of both fractions, the first fraction by the denominator of the second fraction and the second fraction by the denominator of the first fraction. We get equivalent fractions with the same  denominators, thus
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Decimal fractions
Decimal fractions are vulgar fractions whose denominator is a power of ten. Or, it is a fraction written in the place-value notation with base 10 preceded by dot, after which each successive digit indicates a multiple of  the successive negative powers of 10.
Example:
Adding and subtracting like fractions
To add or subtract two fractions with the same denominator, add or subtract the numerators and write the sum over the common denominator.
Examples:
Adding and subtracting fractions
To add or subtract fractions with different denominators: First find the least common denominator (the smallest number that can be divided by each denominator). Write equivalent fractions using this denominator. 
Then add or subtract the fractions.
Examples:
Multiplying fractions
To multiply a whole number by a fraction means to multiply it by a numerator and to divide a product by a denominator. 
When two fractions are multiplied, the result is a fraction with a numerator that is the product of the fractions' numerators and a denominator that is the product of the fractions' denominators.
Examples:
Reciprocal fractions 
The fractions a/b and b/a are reciprocals. Reciprocal fractions are two fractions whose product is 1.  
Dividing fractions
To divide a number by a fraction, multiply the number by the reciprocal of the fraction. 
To divide mixed numbers, you should always convert them to improper fractions, then multiply the first number by the reciprocal of the second. 
To divide a fraction by a whole number, write the whole number as an improper fraction with a denominator of 1, then multiply as fractions.
    or
Examples:
 
Simplifying complex fractions
Complex fractions or compound fractions are fractions in which the numerator and/or denominator contain fractions.
To simplify complex fractions, change the complex fraction into a division problem, i.e., divide the numerator by the denominator. 
Examples:
 
Beginning Algebra Contents A
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