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Weight                                                              Mental Maths

            You have learnt to measure weight of an object in grams            Convert the following:
            and kilograms. Have you ever wondered how a goldsmith              (a)  6,000 mg to g
            or any jeweller weighs small pieces of jewellery!  They            (b)  7 mg to g
            use weights that are smaller than grams.  These are of             (c)  4,750 g to kg
            milligrams (mg).                                                   (d)  525 g to kg


              1,000 g = 1 kg         1 g = 1,000 mg
                      1                         1
             1 g =         kg        1 mg =          g
                    1,000                     1,000


            Example 2:      Fill in the blanks.

                            (a)  2 kg 350 g = ______ g        (b)  6,210 g = ______ kg ______ g
                            (c)  2 g 325 mg ______ mg

            Solution:       (a)          1 kg  =  1,000 g
                                     So, 2 kg  =  2 × 1,000 g = 2,000 g

                                  2 kg 350 g  =  2,000 g + 350 g   = 2,350 g
                            (b)      6,210 g  =  6,000 g + 210 g
                                               =  6 kg + 210 g

                                               =  6 kg 210 g
                            (c)           2 g  =  2,000 mg

                                 2 g 325 mg  =  2,000 mg + 325 mg
                                               =  2,325 mg


            Capacity
                                                                                Mental Maths
            Capacity is measured in kilolitres (kL), litres (L) and            Convert the following:
            millilitres (mL).
                                                                               (a)  4 L to kL
             1 kL = 1,000 L          1 L = 1,000 mL                            (b)  2,000 L to kL
                                                                               (c)  5,000 mL to L
             1 L =    1   kL         1 mL =     1   L                          (d)  250 mL to L
                   1,000                      1,000

            Example 3:      Fill in the blanks.

                            (a)  3 kL 475 L = ______ L            (b)  6,245 L = ______ kL ______ L
                            (c)  3 L 625 mL = ______ mL           (d)  1,045 mL = ______ L _____ mL

            Solution:       (a)         1 kL = 1,000 L
                                    So, 3 kL = 3 × 1,000 L = 3,000 L

                                  3 kL 475 L = 3,000 L + 475 L = 3,475 L



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