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Bananas bought by Sarla =  d4 +     150   n kg = 4.15 kg
                                                              , 1 000
                          Total fruit bought by Sarla = (4.8 + 4.15) kg = 8.95 kg

                          Clearly, Sarla bought more fruits.
            Example 9:  By how much is the sum of 23.12 and 19.015 greater than their difference?

            Solution:              Sum of 23.12 and 19.015 = 23.12 + 19.015 = 42.135
                            Difference of 23.12 and 19.015 = 23.12 – 19.015 = 4.105
                          To find how much greater is the sum than their difference, we evaluate
                          42.135 – 4.105
                                           i.e.,  42.135

                                                 – 4.105
                                                 38.030    Hence, the sum is 38.03 more than the difference.


              EXERCISE 3.1
               1.  Express in rupees:  (a) 17 paise     (b)  55 rupees 55 paise

               2.  Convert the following from smaller unit to bigger unit:
                  (a)  25 cm in m        (b)  135 cm in km       (c)  20 mm in m         (d)  200 mm in km
               3.  Express in kg:  (a) 39 g in kg                (b)  3 kg 380 g in kg
               4.  Write the following decimals in expanded form: (a) 12.79    (b) 234.95

               5.  How much less is 17 km from 28.3 km?
               6.  Radha bought 2 kg 250 g potatoes, 1 kg 300 g cabbage, 1 kg 450 g peas, 2 kg 670 g onions
                 and 275 g ginger. Reshma bought 3 kg 10 g onions, 1 kg tomatoes, 560 g grapes, 1 kg
                 780 g papaya and 1 kg 655 g apples from a fruit and vegetable store. Who bought more in
                 terms of quantity and by how much?


            Multiplication of Decimal Numbers by 10, 100, 1,000, etc.
            When a decimal number is multiplied by 10, 100 or 1,000, the digits in the product remain the
            same as in the decimal number but the decimal point in the product shifts to the right by as many
            places as there are zeros after one, i.e.,
            (a)  When a decimal number is multiplied by 10, the decimal point is shifted to the right by one
                place.
            (b)  When a decimal number is multiplied by 100, the decimal point is shifted to the right by two
                places.
            (c)  When a decimal number is multiplied by 1,000, the decimal point is shifted to the right by
                three places.
            Example 10: Find:
                          (a)  3.2 × 10          (b)  453.7 × 10        (c)  268.07 × 10
                          (d)  42.1 × 100        (e)  0.83 × 100        (f)  0.09 × 1,000
            Solution:     (a)  3.2 × 10 = 32                            (b)  453.7 × 10 = 4,537
                          (c)  268.07 × 10 = 2,680.7                    (d)  42.1 × 100 = 4,210
                          (e)  0.83 × 100 = 83                          (f)  0.09 × 1,000 = 90


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