Page 21 - ICSE Math 6
P. 21

EXERCISE 1.1

                      1.  Consider the number 51,078 to answer the following.

                        (a)  The local value of 1 = __________          (b)  The true value of 1 = __________
                        (c)  The local value of 0 = __________          (d)  The true value of 5 = __________

                        (e)  The local value of 7 = __________          (f)  The local value of 5 = __________
                      2.  Write the place value of two 3s in 73,231 and find their difference.
                      3.  Which digit in the number 4,578 has the same face value and place value?

                      4.  Find the sum of the face value and the place value of the digit 2 in 720.
                      5.  Insert commas and write the number names according to the Indian system of numeration.

                         (a)  85055                   (b)  39754081                 (c)  47481405
                      6.  Insert commas and write the number names according to the International system of numeration.

                         (a)  7835410                 (b)  67234189                 (c)  24892348
                      7.  Which number is smaller?
                        (a)  12,567 or 12,657                           (b)  4,50,98,145 or 4,51,87,546

                        (c)  5,67,30,001 or 4,98,71,002                 (d)  3,49,88,067 or 3,49,89,167
                      8.  Arrange the following numbers in descending order.

                         78,13,018      70,99,954      1,48,05,654      1,95,45,678      2,95,00,141      2,95,10,200

                    Forming Numbers
                    To form numbers using the given digits, we can arrange the digits:
                    •  with repetition,

                    •  without repetition, and
                    •  in an order if needed

                    Without repetition of digits
                    To form numbers using the given digits without any repetition, use each of the given digits only once.
                    For example, all the possible numbers that can be formed using the digits 2 and 6 without repetition
                    of digits are 26 and 62.

                      The numbers 22 and 66 are not considered as no digit is to be repeated.


                    With repetition of digits
                    If repetition of digits is allowed, then we use the given digits any number of times accordingly.

                    Example 6:  Using each of the digits 3 and 7 at least once form all the possible 3-digit numbers.
                    Solution:     All the possible 3-digit numbers that can be formed are: 337, 373, 733, 377, 737 and
                                  773.

                    Forming the smallest and the greatest number

                    •  To form the smallest number with the given digits, place the smallest digit at the extreme left
                       position, and then place the remaining digits in ascending order of their values.


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