Chapter 2 Whole Numbers Ex 2.1 Solutions
Question - 1 : - Write the next three natural numbers after 10999.
Answer - 1 : -
Next three natural numbers after 10999 are
11000, 11001, 11002
Question - 2 : - Write the three whole numbers occurring just before 10001.
Answer - 2 : -
3 whole numbers just before 10001 are
10000, 9999, 9998
Question - 3 : - Which is the smallest whole number?
Answer - 3 : -
The smallest whole number is 0.
Question - 4 : - How many whole numbers are there between 32 and 53?
Answer - 4 : -
Whole numbers between 32 and 53 = 20 (53 − 32 − 1 = 20)
(33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
Question - 5 : - Write the successor of:
(a) 2440701 (b) 100199
(c) 1099999 (d) 2345670
Answer - 5 : -
(a) 2440701 + 1 = 2440702
(b) 100199 + 1 = 100200
(c) 1099999 + 1 = 1100000
(d) 2345670 + 1 = 2345671
Question - 6 : - (a) 2440701 + 1 = 2440702
(b) 100199 + 1 = 100200
(c) 1099999 + 1 = 1100000
(d) 2345670 + 1 = 2345671
Answer - 6 : -
(a) 94 − 1 = 93
(b) 10000 − 1 = 9999
(c) 208090 − 1 =208089
(d) 7654321 − 1 = 7654320
Question - 7 : - In each of the following pairs of numbers, state which whole number is on the left of the other number on the number line. Also write them with the appropriate sign (>, <) between them.
(a) 530, 503 (b) 370, 307
(c) 98765, 56789 (d) 9830415, 10023001
Answer - 7 : -
(a) 530, 503
As 530 > 503,
503 is on the left side of 530 on the number line.
(b) 370, 307
As 370 > 307,
307 is on the left side of 370 on the number line.
(c) 98765, 56789
As 98765 > 56789,
56789 is on the left side of 98765 on the number line.
(d) 9830415, 10023001
Since 98, 30, 415 < 1, 00, 23, 001,
98,30,415 is on the left side of 1,00,23,001 on the number line.
Question - 8 : - Which of the following statements are true (T) and which are false (F)?
(a) Zero is the smallest natural number.
(b) 400 is the predecessor of 399.
(c) Zero is the smallest whole number.
(d) 600 is the successor of 599.
(e) All natural numbers are whole numbers.
(f) All whole numbers are natural numbers.
(g) The predecessor of a two digit number is never a single digit number.
(h) 1 is the smallest whole number.
(i) The natural number 1 has no predecessor.
(j) The whole number 1 has no predecessor.
(k) The whole number 13 lies between 11 and 12.
(l) The whole number 0 has no predecessor.
(m) The successor of a two digit number is always a two digit number.
Answer - 8 : -
(a) False, 0 is not a natural number.
(b) False, as predecessor of 399 is 398 (399 − 1 = 398).
(c) True
(d) True, as 599 + 1 = 600
(e) True
(f) False, as 0 is a whole number but it is not a natural number.
(g) False, as predecessor of 10 is 9.
(h) False, 0 is the smallest whole number.
(i) True, as 0 is the predecessor of 1 but it is not a natural number.
(j) False, as 0 is the predecessor of 1 and it is a whole number.
(k) False, 13 does not lie in between 11 and 12.
(l) True, predecessor of 0 is −1, which is not a whole number.
(m) False, as successor of 99 is 100.