Page 88 - C:\Users\azizu\Documents\Flip PDF Professional\Matematics-Form-1-1\
P. 88

What are equivalent ratios?
                                                                                     LEARNING
                                                                                          STANDARDS
                 Observe the equivalent fractions that represent the shaded      Identify and determine
                 parts in the diagram below.                                     the equivalent ratios in
                                                                                 numerical, geometrical or
                                                             The areas of the    daily situation contexts.
                                                             shaded parts
                                                             are always of
                                                             the same size.
                       1            2             6
                       2            4             12                                                          CHAPTER
                     ÷  2      ×  3                                                                           4
                 1   =    2   =    6                                               Equivalent ratios
                 2        4        12                                              can be found by
                                                                                   writing the ratios as
                     ÷  2      ×  3                                                equivalent fractions.
                 These fractions can be expressed in ratios as follows.
                                   ÷  2           ×  3


                             1  :  2   =   2  :  4   =   6  :  12
                                                                               Think      Smart
                                        ÷  2          ×  3
                                                                                               1
                                                                                                  1
                      1 : 2, 2 : 4 and 6 : 12 are known as equivalent ratios.     Are 23 : 46 and   :
                                                                                               6
                 To find an equivalent ratio, multiply or divide each part of     equivalent to 1 : 2? 3
                 the ratio by the same whole number.
                             2

                 Which of the following ratios are equivalent to 27 : 45?

                                                            1   5
                         9 : 15      5 : 3     54 : 90         :
                                                            2   6


                 27 : 45 = 27  × 2  : 45  × 2    27 : 45 = 27  ÷ 9  : 45  ÷ 9
                        = 54 : 90                     = 3 : 5                       Ratio 3 : 5 ≠ 5 : 3.

                                                               1          1
                 27 : 45 = 27  ÷ 3  : 45  ÷ 3    27 : 45 = 27  ×    : 45  ×
                                                              54          54
                        = 9 : 15
                                                      =  1   :   5
                                                         2   6
                                                                                    5
                                                                                                5
                                                                                        1
                 Thus, ratios which are equivalent to 27 : 45 are                1  :   =    × 54  :    × 54
                                                                                 2  6   2       6
                                     1   5
                 9 : 15, 54 : 90 and    :   .                                         = 27 : 45
                                     2   6
                                                                                                       77
                                                                        Ratios, Rates and Proportions



       04 TB Math F1.indd   77                                                                        11/10/16   12:12 PM
   83   84   85   86   87   88   89   90   91   92   93