Page 79 - Start Up Mathematics_3
P. 79

Worksheet




                                                     Multiplication

            You have learnt tables upto 15. These tables can be written with the help of the grid
            given below.


               X    1    2   3    4   5    6    7   8    9   10   11  12   13  14   15   16  17   18  19   20

               1    1    2   3    4   5    6    7   8    9   10   11  12   13  14   15   16  17   18  19   20
               2    2    4   6    8   10   12  14   16  18   20   22  24   26  28   30   32  34   36  38   40
               3    3    6   9   12   15   18  21   24  27   30   33  36   39  42   45   48  51   54  57   60

               4    4    8   12  16   20   24  28   32  36   40   44  48   52  56   60   64  68   72  76   80
                5   5   10   15  20   25   30  35   40  45   50   55  60   65  70   75   80  85   90  95   100

                6   6   12   18  24   30   36  42   48  54   60   66  72   78  84   90   96  102  108  114  120
                7   7   14   21  28   35   42  49   56  63   70   77  84   91  98   105  112  119  126  133  140
                8   8   16   24  32   40   48  56   64  72   80   88  96  104  112  120  128  136  144  152  160

                9   9   18   27   36  45   54  63   72   81  90   99  108  117  126  135  144  153  162  171  180
               10   10  20   30   40  50   60  70   80   90  100  110  120  130  140  150  160  170  180  190  200
               11   11  22   33   44  55   66  77   88   99  110  121  132  143  154  165  176  187  198  209  220

               12   12  24   36   48  60   72  84   96  108  120  132  144  156  168  180  192  204  216  228  240
               13   13  26   39   52  65   78  91   104  117  130  143  156  169  182  195  208  221  234  247  260
               14   14  28   42   56  70   84  98   112  126  140  154  168  182  196  210  224  238  252  266  280

               15   15  30   45   60  75   90  105  120  135  150  165  180  195  210  225  240  255  270  285  300
               16   16  32   48   64  80   96  112  128  144  160  176  192  208  224  240  255  272  288  304  320

               17   17  34   51   68  85  102  119  136  153  170  187  204  221  238  255  272  289  306  323  340
               18   18  36   54   72  90  108  126  144  162  180  198  216  234  252  270  288  306  324  342  360
               19   19  38   57  76   95  114  133  152  171  190  209  228  247  266  285  304  323  342  361  380

               20   20  40   60  80   100  120  140  160  180  200  220  240  260  280  300  320  340  360  380  400

            Suppose you want to find 15 × 7.

            Read row 15 of column 7. You get 105 which is the product of 15 × 7.

            Now using the grid, find the following products.

               (a)  16 × 3 =                   (b)  18 × 7 =                  (c)  17 × 5 =


                (d)  19 × 9 =                  (e)  20 × 8 =                 (e)  15 × 9 =

            Also, write the tables of 16 to 20 using the grid.




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