Exercise-2.1
1. Write the next three natural numbers after 10999.
Solution:
The next three natural number after 10999 are:
10999+1, 10999+2, 10999+3
i.e. 11000, 11001, 11002
2. Write the three whole numbers occurring just before 10001.
Solution:
The next three natural number after 10999 are:
10999+1, 10999+2, 10999+3
i.e. 11000, 11001, 11002
3. Which is the smallest whole number?
Solution: 0 is the smallest whole number.
4. How many whole numbers are there between 32 and 53?
Solution:
there are (53 - 32) - 1 = 21 - 1 = 20
whole numbers between 32 and 53 are 20.
5. Write the successor of :
(a) 2440701 (b) 100199 (c) 1099999 (d) 2345670
(a) 2440701
Solution: 2440701 + 1 = 2440702
(b) 100199
Solution: 100199 + 1 = 100200
(C) 1099999
Solution: 1099999 + 1 = 1100000
(d) 2345670
Solution: 2345670 + 1 = 2345671
6. Write the predecessor of :
(a) 94 (b) 10000 (c) 208090 (d) 7654321
(a) 94
Solution: 94 - 1= 93
(b) 10000
Solution: 10000 – 1= 9999
(c) 208090
Solution: 208090 – 1= 208089
(d) 7654321
Solution: 7654321 – 1= 7654320
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
(a) 530, 503
Solution: Here, 503 lies on the left of the 530 on number line
Therefore, 530 > 503 or 503<530
(b) 370,307
Solution: Here, 307 lies on the left of the 370 on number line
Therefore, 307<370 or 370>307
(c) 98765, 56789
Solution: Here, 56789 lies on the left of the 98765 on number line
Therefore, 56789 < 98765 or98765 > 56789
(d) 9830415, 10023001
Solution: Here, Here, 10023001 lie on the left of the 9830415on number line
Therefore, 9830415<0023001 or 9830415>10023001
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 :
(a) Fallse
(b) False
(c) True
(d) True
(e) True
(f) False
(g) False
(h) False
(i) True
(j) False
(k) False
(l) True
(m) False
