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                       1A
                       1A   Numbers

                          Number fact                                            =   1   −   1
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                                                                                  3145   0.03
                     1   (a)  26                               [1]             c = −0.030                       [2]
                         (b)  23 and 29                        [1]            1   a – b
                         (c)  27                               [1]        (b)   c   =   ab
                         (d)  25                               [1]                 ab
                     2   (a)  100                              [1]             c =  a – b                       [2]
                         (b)  –28                              [1]    11  0.6 hours = 36 minutes
                         (c)  100                              [1]        Distance travelled =  50π × 100 × 36
                         (d)   √7                              [1]                          100 × 1000
                                  3
                     3   (a)   π  and √4                       [1]                       = 5.655 km             [2]
                             3
                         (b)  0, 64 and 3 2                    [1]         Standard form
                         (c)  0.5                              [1]
                         (d)  64                               [1]    1   (a)  70200.05   70200                 [2]
                                                                                     ∼
                     4   59 – 7 = 52                           [2]        (b)  2811.484   2811                  [2]
                                                                                     ∼
                     5   11, 13, 17, 19                        [1]        (c)  1232010000                       [2]
                                                                                   ∼
                                                                          (d)  5343.5   5344                    [2]
                          Inequalities                                    (e)  16853932.58   16853933           [2]
                                                                                        ∼
                                                                                        ∼
                                                                          (f)  11992578.95   11992579           [2]
                     1   cos 50° <   42   < tan 50° < 1.05 × 10 1   [2]  2   (8.97 × 10 ) – (6.2 × 10 )
                                                                                             10
                                                                                  12
                                 50                                       = 10 (8.97 × 10  – 6.2)
                                                                             10
                                                                                      2
                                           1
                                                                                    12
                              3
                     2   0.3  <  √0.3 < 10  <  0.3             [2]        = 8.908 × 10    2                     [2]
                                      0.3
                           2
                                                                            38
                     3   1  < 3.14 < π <  22                   [2]    3   10 (4.05 + 4.05 × 10 )                [2]
                                                                          = 4.0905 × 10

                         π
                                                                                     40
                                      7
                     4   0.879 > 0.879 >  0.879 >   68         [2]    4   6.5 × 10 2                            [2]
                                             78                       5   (a)  11809 × 85 + 8532 × 55
                     5   2.35 × 10  > 2.84 × 10  > 9.72 × 10  > 1.089 × 10 –3        = 1473025                  [2]
                                          0
                                                    –2
                                3
                                                               [2]        (b)  1.473025 × 10 6                  [2]
                                                                      6   (4.5 × 60) × 24 × 365
                          Rounding off                                    = 2365200
                                                                          = 2.3652 ×10 6                        [2]
                                                                                  –3
                     1   (a)  41.1484424                       [1]    7   1.085 × 10  × 80000
                         (b)  41                               [2]        = 8.68 × 10 1                         [2]
                     2   3.95   4.0                            [2]
                             ∼
                         √9  × 40  3 × 40                                  Recurring decimals
                     3           =      =12                    [2]
                         3
                         √1000      10                                1    Let x = 0.26
                     4   211929381.5   212000000               [2]          10x = 2.6
                                   ∼
                     5   (a)   5.413                           [1]         100x = 26.6
                         (b)  5.41                             [1]          90x = 24
                     6   24 × 1  = 8                           [2]           x =  24   =   4
                           3                                                     90  15
                              ∼
                     7   1.047   1.0                           [2]    2    Let x = 0.34                         [2]
                               ∼
                     8   12531.6   13000                       [2]         100x = 34.34
                     9   0.006239   0.0062                     [2]          99x = 34
                                ∼
                             1    1   1
                     10  (a)    =    −   a                                   x =  34
                             c
                                  b
                                                                                99                              [2]
                                                                                                     Answers    153
         Answers.indd   153                                                                                      15/03/2022   11:08 AM
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