Page 184 - ICSE Math 5
P. 184

Relationship between Fractions, Decimals and Percentages

                    Since percentages are the fractions having denominators as 100, they can be easily converted
                    and written in a decimal form.
                                         62
                    For example, 62% =        = 0.62.
                                         100
                    Similarly, decimals can also be converted to percentages.
                                          2                    41
                    For example, 0.02 =       = 2% and 0.41 =       = 41%.
                                         100                   100
                    Now let’s learn conversion of fractions to percentages, percentages to fractions, decimals to
                    percentages and percentages to decimals.
                    Conversion of a Fraction to Percentage and Vice Versa

                    Conversion of a fraction to percentage

                    To convert a fraction to percentage, we multiply the given fraction by 100 and put the per cent (%)
                    sign or we change the fraction to equivalent fraction with 100 as the denominator, where its
                    numerator gives the percentage.

                    Example 2:  Convert the following fractions to percentage.
                                 (a)  2            (b)                 12
                                       5                                 25

                                       2   2    20                                   12   12     4
                    Solution:     (a)    =   × 100% = 2 × 20% = 40%            (b)     =    × 100% = 12 × 4% = 48%
                                       5   5                                         25   25
                                       Alternatively,                                Alternatively,

                                     2  =  2 × 20  =   40   = 40%                   12  =  12 × 4  =   48   = 48%
                                       5   5 × 20 100                                25   25 × 4 100


                    Conversion of a percentage to fraction

                    To convert a percentage to fraction, we remove the % sign and divide the number of the percentage
                                              1
                    by 100 or multiply it by     . Then we reduce the fraction to its lowest term, if needed.
                                             100

                    Example 3:  Convert the following percentages to fractions. Reduce to the lowest terms, if
                                  possible.
                                                                                    1
                                  (a) 27%     (b) 75%     (c) 6 %
                                                                                    2
                                                                      15  3
                                              27                   75        3           1     13     13     1     13
                    Solution:     (a) 27% =         (b) 75% =             =    (c) 6 % =       % =      ×     =
                                              100                 100        4           2     2       2   100    200
                                                                      20  4

                    Conversion of a Decimal to Percentage and Vice Versa

                    Conversion of a decimal to percentage

                    To convert a decimal to percentage, we change the given decimal to fractional form and then
                    multiply it by 100 and put the % sign.

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