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    E:\Working\Focus_Learning\Math_Genius_3_(11-09-2024)\Open_Files\CHAP_04
                 \ 12-Sep-2024               Surender Prajapati   Proof-5                     Reader’s Sign _______________________ Date __________

                  Multiplying by 10, 20, 30, ..., 90, anD 100, 200, 300, ..., 900

                  Multiplying by 10

                  To multiply a number by 10, write a ‘0’ to the right of the number.
                  Look at the following multiplications.

                  Examples:  (a) 3 × 10 = 30                 (b) 12 × 10 = 120            (c) 324 × 10 = 3240

                  Multiplying by 20, 30,..., 90

                  To multiply a number by 20, 30, 40, ..., 90, first multiply the number without 0. Then,

                  write a ‘0’ to the right of the product obtained.
                  Examples:  (a) 12 × 20 = 240               (b) 36 × 30 = 1080           (c) 26 × 60 = 1560

                  Multiplying by 100           12 × 2                       36 × 3                       26 × 6

                  To multiply a number by 100, write two zeros (00) to the right of the number.

                  Examples:  (a) 1 × 100 = 100               (b) 5 × 100 = 500            (c) 17 × 100 = 1700

                  Multiplying by 200, 300, ..., 900

                  To multiply a number by 200, 300, 400, ..., 900, first multiply the number without 00.
                  Then, write two zeros (00) to the right of the product obtained.

                  Examples:  (a) 1 × 200 = 200               (b) 12 × 300 = 3600          (c) 14 × 700 = 9800
                                               1 × 2                         12 × 3                       14 × 7

                           Think and Answer
                       Which pair of numbers best completes the given multiplication fact        × 100 =

                       ●   65  and  650              ●   10  and  1000               ●   7  and  70              ●   1  and  101

                           practice time 4e

                  1.  Fill in the blanks.

                       (a)  _____ × 10 = 1000           (b)  6 × 100 = _____             (c)  7 × _____ = 3500
                       (d)  _____ × 3 = 2100            (e)  _____ × 60 = 480             (f)  11 × 60 = _____

                       (g)  5 × 20 = _____              (h)  8 × _____ = 320              (i)  _____ × 20 = 120

                  2.  Multiply the following by expanding the bigger number.

                       (a)  96 × 9                      (b)  89 × 5                      (c)  36 × 4

                       (d)  56 × 9                      (e)  64 × 8                       (f)  82 × 6

                  78                                                                                    Mathematics-3

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