1, Write down the Successer of each of the following
   (i) 3008  (ii) 5013
The successer of a given whole number is 1 more than the given number.
(i) Successor of 3008 = 3008 + 1
                                = 3009
(ii) Successor of 5013478 = 5013478 + 1
                                      = 5013479

2, Write down the predecessor of each of the following
  (i) 4000    (ii) 616264
The predecessor of a given whole number is 1 less than the given number

(i) Predecessor of 4000 = 4000 - 1
                                  = 3999
(ii) Predecessor of 616264 = 616264 - 1 = 616263

3, Write the next three consecutive natural numbers.
      (i) 98              (ii) 835
(i)    98 + 1 = 99,    99 + 1 = 100,    100+1 = 101
  ∴ Next three consecutive natural numbers after 98 are 99,100,101
(ii) 835 + 1 = 836, 836 + 1 = 837, 837 + 1 = 838
 ∴ Next three consecutive numbers after 835 are 836,837,838.

4, Write the least three even numbers.
 First even natural number is 2.
 ∴ least three even numbers are 2,4,6

5, While whether each of the following statement is true or false
(i) The smallest counting number is 0.
(ii) Every natural number is a whole number.
(iii) The numeral XXIII represents a natural number.
(i)  False .The counting numbers are 1,2,3,4,--------
    ∴ Smallest counting number is 1
(ii) True
(iii) True .The roman numeral ,XXIII represents 23

6, State the place value of 7 in each of the following
    (i) 287     (ii) 73,596
(i) In 287,7 is in the Unit place
 ∴ Place value of 7 in 287 = 7× 1 = 7
 (ii) In 73,596 , 7 is in the ten thousand place
  ∴ Place value of 7 in 73,596 = 7 × 10,000
                                             = 70,000

7, Replace each blank with a power of 10,with 10 or with 1.
     (a) 853 = (8×__) + (5×__) + (3×__)
      (b) 3,891=(3×__) + (8×__) + ( 9×__) + ( 1×__)

 (a) 853, 3 is in ones place(ie 10 ⁰ )
   5 is in tens place (ie,10 ¹)
   8  is in hundreds place (10 ²)
   ∴ 853  = 8×10² + 5× 10 ¹ + 3×10 ⁰
(b) In 3,891, is in 10⁰ position , 9 in 10¹ position,
    8 in 10² position and 3 in 10 ³ position
 ∴ 3891 = 3×10³ + 8×10² + 9×10¹ + 1×10⁰
8, Write the numeral for (5×10⁴)+(7×10³)+(8×10²)+(1×10)+(6×1)
       5×10⁴ = 50000
        7×10³ = 7000
         8×10² = 800  , 1×10 = 10 and 6×1 = 6.
         ∴ Required answer = 50000+7000+800+10+6
                                      = 57816

9, Rearrange the numbers from largest to smallest
     17800 ;  17903 ; 17308 ; 17400
                   
    The digits in the thousands and Ten thousands place are same for all the numbers.
    So compare the digits in hundreds place.Of these 9 is biggest,then 8 , 4,3 respectively
           ∴ The numbers from largest to smallest are 17903 , 17800 , 17400 , 17308
10, How many times does the digit 1 occur in ten's place in the numbers from 100 to 1000 ?
          The numbers from 100 to 1000 having the digit 1 in ten's place are 110 to 119 , 210 to 219 , 310 to 319 ,
           410 to 419 , 510 to 519 , 610 to 619,710 to 719, 810 to 819 and 910 to 919 .Thus in every hundred numbers
             from 100 to 1000,there are 10 numbers with 1 in there ten's place.
             ∴ Total number of numbers from 100 to 1000 having 1 in ten's place = 10×9 = 90
              ∴ The digit 1 occurs 90 times in ten's place in the numbers from 100 to 1000

11, How many different 3 digit numbers can be formed by using the digits 0,2,5 without repeating any digit in the number ?
          We cannot put 0 at the hundred's place because in that case the number formed would be of 2 digits only .If we have 2 at the hundred's place,the possible 3 - digit numbers formed are 205 and 250.If we put 5 at the hundreds place,the possible 3 - digit numbers formed are 520 and 502 .Thus ,the total number of 3 - digit numbers formed with the digits 0,2 and 5 is 4 .

12, Write all three digit numbers formed by using 3,6 and 8.Taking each digit only once in each  number.
          Keeping 3 at the hundreds place the numbers are 568 and 386 .Keeping 6 at the hundreds place the numbers formed are 683 and 638.Keeping 8 and the hundreds place,the numbers formed are 836 and 863.
        So the required numbers are 368,386,638,683,863,836.

13,Write 10075302 in words and re-arrange the digits to get the smallest number .
        The number 100 , 75 , 302 is one crore seventy five thousand three hundred and two.
        In forming the smallest number with the given digits we will put the digits in the increasing order,thus putting the target digit at the extreme right.
             ∴ Smallest number formed with the given digits is 1002357.

14, Write the greatest 7 digit number having three different digits.
         Since we have to write the greatest 7 digit number having 3 different digits,we will pick up the three greatest digits 7 , 8 , 9 out of the digits 0,1,2,3,4,5,6,7,8,9
              ∴ The greatest 7 dogit number is 9999987.

15, Write the smallest 7 digit number having four different digits.
           Taking the four smallest digits 0,1,2,3 the smallest 7 - digit number having four different digits is 1000023.

16, Find the difference of the place value and face value of the digit 3 in 613728.
          Face value of 3 in the number  613728 is 3
           Place value of 3 in the number 613728 is 3000
           ∴ Required difference = 3000 - 3 = 2997

17, How many numbers in all do we have with 3 digits.
           Smallest 3 - digit number = 100
            Greatest 3 - digit number = 999
             3 digit numbers are from 100 to 999.
             ∴ Number of 3 digit numbers = 999 - 99 = 900

18, Express the numeral for fifty six lakh seventy two thousand nine hundred eight.
          The number contains fifty six lakhs,seventy two thousands nine hundreds and eight .
           Displaying this fact in the place value chart.
                               
         The numeral for the given number is 5672908.

19, Express 4,32,207 in expanded form

        
         ∴  Expand form of 4,32,207
               = 4×10⁵ + 3×10⁴+2×10³ + 2×10² + 0×10¹ +7×10⁰

20, Write down the three whole numbers just preceeding 5510001.
          5510001 - 1 = 5510000
          5510000 - 1= 5509999
          5509999 - 1= 5509998