Whole Numbers

Whole Numbers


Exercise 2.1


Ex 2.1 Question 1.


Write the next three natural numbers after 10999.
Solution-

The next three natural numbers after 10999 are

10999 +1 =11000

11000 + 1 =11001

11001 + 1 =11002.


Ex 2.1 Question 2.


Write three whole numbers occurring just before 10001.
Solution-

Three whole numbers just before 10001 are
10001 – 1 = 10000
10000 – 1 = 9999
9999 – 1 = 9998


Ex 2.1 Question 3.


Which is the smallest whole number?
Solution-
0 (Zero) is the smallest whole number.


Ex 2.1 Question 4.


How many whole numbers are there between 32 and 53?
Solution-

53 -32 -1 = 20
There are 20 whole numbers between 32 and 53.

(33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)


Ex 2.1 Question 5.


Write the successor of:
(a) 2440701
(b) 100199
(c) 1099999
(d) 2345670
Solution-
(a) Successor of 244070 is

244070 + 1 = 244071

(b) Successor of 100199 is

100199 + 1 = 100200

(c) Successor of 1099999 is

1099999 + 1 = 1100000
(d) Successor of 2345670 is

2345670 + 1 = 2345671


Ex 2.1 Question 6.


Write the predecessor of:
(a) 94
(b) 10000
(c) 208090
(d) 7654321
Solution-
(a) Predecessor of 94 is

94 – 1 = 93

(b) Predecessor of 1000 is

10000 – 1 = 9999

(c) Predecessor of 208090 is

208090 -1 = 208089

(d) Predecessor of 7654321 is

7654321 – 1 = 7654320


Ex 2.1 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
Solution-
(The smaller number is always on the left side of the greater number on the number line.)
(a) 530, 503
530 > 503
Hence, 503 appears on the left side of 530 on the number line.

(b) 370, 307
307 > 370
Hence, 307 appears on the left side of 370 on the number line.

(c) 98765, 56789
98765 > 56789

Hence, 56789 appears on the left side of 98765 on the number line.

(d) 9830415, 10023001
9830415 > 10023001
Hence, 9830415 appears on the left side of 10023001 on the number line.


Ex 2.1 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.
Solution:
(a) False (F)
(b) False (F)
(c) True (T)
(d) True (T)
(e) True (T)
(f) False (F)
(g) False (F)
(h) False (F)
(i) True (T)
(J) False (F)
(k) False (F)
(l) True (T)
(m) False (F)