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Logarithms


           Solution                                    (c)   (6 10×  6 ) ( 2 10×−  4 ) (6 10×=  6 ) (0.02 10−  ×  6 )
                          4 10
           (a)      4 10  8  =   8
                 5 10  5  5 10 5                 (6 10×  6 ) ( 2 10×−  4 ) (6 10×=  6 ) (0.02 10−  ×  6 )
                             
                        =  0.8 10 3                                 =  (6 0.02) 10−  ×  6
                              = 8 × 10  × 10
                        =  8.0 10   − -1 1  10 3 3                 = 5.98 × 10 6
          FOR ONLINE READING ONLY
                        = 8 × 10
                             
                        = 8.0 10 2 2                   (d)   3.14 10×  −  2  −  4.03 10×  −  3 =  3.14 10×  −  2  −  0.403 10×  −  2
           Therefore,   4 10  8   = 8 × 10 .                = 3.14−10 −0.403×10      −2
                                      2
                                                                        −2
                  4 848     5 5  =  4 848 10 -  5 -
                      5 10 10´
                                     ´
                    20 10 2      20    10 2                  = (3.14−0.403)×10   −2
                      ´
           (b)                                                                                       Mathematics for Secondary Schools
                                     ´
                              =  242.4 10  7 -                = 2.737 10×  − 2
                                     ´
                              =  242.4 10  7 -
                                                      Exercise 6�1
                              =  2.424 10 ´  2  10 - 7  1.  Write each of the following numbers
                                     ´
                                     ´
                              =  2.424 10  5 -             in standard form:
           Therefore,   4 848 10´  - 5  =  2.424 10´  - 5    .  (a) 31065      (b) 95.1
                         20 10´  2                        (c) 9999             (d) 6
                                                                1
           Example 6�5                                    (e)                  (f) 69.03
                                                               100
           Evaluate each of the following, giving         (g) 253009115        (h) 5.41
           the answers in standard form:
                                                           (i) 0.0004068       (j) 7.245
           (a)  3 10×  4  +  4.32 10×  3
                                                          (k) 1985             (l) 0.000008
                     −3
           (b)  5×10 +6×10     −5
           (c)  (6 10×  6 ) ( 2 10×−  4 )                 (m)  3               (n) 30
                                                               4
           (d)  3.14 10×  −  2  − 4.03 10×  −  3
                                                          (o) 463.18           (p) 265000
           Solution                                    2.  Write each of the following in
           (a)   3 10 +4.32 10×  4  ×  3 =  3 10×  4  + 0.432 10×  4  decimal numerals:

         3 10 +4.32 10×    4     ×  3 = 3 10×  4 + 0.432 10×  4     (a)  9.10 × 10 5
                               =  (3 0.432) 10+  ×  4     (b)   7.4 × 10 – 4

                          =  3.432 10×  4                 (c)   3 × 10 0  4
           (b)   5 10×  −  3 + 6 10×  −  5 =  5 10 +0.06 10×  −  3  ×  −  3  (d)  26.5 × 10 4

          5 10×  −  3 + 6 10×  −  5 = 5 10 +0.06 10×  −  3  ×  −  3  (e)  2.74 × 10
                                                                        –3
                          = (5 0.06) 10×+  − 3            (f)   4.2 × 10
                                                          (g)   3.68 × 10 3
                          = 5.06 10×  − 3                 (h)   8.67 × 10 –2



                                                   119
           Student's Book Form Two


                                                                                          11/10/2024   20:12:48
     MATHEMATIC F2 v5.indd   119                                                          11/10/2024   20:12:48
     MATHEMATIC F2 v5.indd   119
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