NCERT Solutions for Class 6 Maths - Whole Numbers

Exercise 2.1

Q1. Write the next three natural numbers after 10999.
Ans: 
⇒ 10,999 + 1 = 11,000
⇒ 11,000 + 1 = 11,001
⇒ 11,001 + 1 = 11,002

Q2. Write the three whole numbers occurring just before 10001.
Ans: 
⇒ 10,001 – 1 = 10,000
⇒ 10,000 – 1 = 9,999
⇒ 9,999 – 1 = 9,998

Q3. Which is the smallest whole number?
Ans: ‘0’ (zero) is the smallest whole number.

Q4. How many whole numbers are there between 32 and 53?
Ans: The whole numbers between 32 and 53 are as follows:
(33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
Hence, there are 20 whole numbers between 32 and 53

Q5. Write the successor of:
(a) 2440701 
(b) 100199
(c) 1099999 
(d) 2345670
Ans: 

A successor is used for the numbers that comes just after any number.

(a) Successor of 2440701 is 2440701 + 1 = 2440702
(b) Successor of 100199 is 100199 + 1 = 100200
(c) Successor of 1099999 is 1099999 + 1 = 1100000
(d) Successor of 2345670 is 2345670 + 1 = 2345671

Q6. Write the predecessor of:
(a) 94 
(b) 10000
(c) 208090 
(d) 7654321
Ans: 

A predecessor is used for the numbers that comes just before any number.

(a) The predecessor of 94 is 94 – 1 = 93
(b) The predecessor of 10000 is 10000 – 1 = 9999
(c) The predecessor of 208090 is 208090 – 1 = 208089
(d) The predecessor of 7654321 is 7654321 – 1 = 7654320

Q7. 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
Ans:
(a) Since, 530 > 503

Hence, 503 is on the left side of 530 on the number line

(b) Since, 370 > 307

Hence, 307 is on the left side of 370 on the number line

(c) Since, 98765 > 56789

Hence, 56789 is on the left side of 98765 on the number line

(d) Since, 9830415 < 10023001

Hence, 9830415 is on the left side of 10023001 on the number line

Q8. 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.
Ans: 
(a) False

Natural numbers start from 1. Therefore, zero is not considered a natural number. 

(b) False

The predecessor of a number is the number that comes immediately before it. The predecessor of 399 is 398, not 400.

(c) True

Whole numbers include all natural numbers along with zero. Therefore, zero is the smallest whole number. 

(d) True

The successor of a number is the number that comes immediately after it. The successor of 599 is 600.

(e) True

Natural numbers are a subset of whole numbers. Therefore, all natural numbers are indeed whole numbers. 

(f) False

Whole numbers include zero, which is not a natural number. Therefore, not all whole numbers are natural numbers.

(g) False

The predecessor of 10, which is a two-digit number, is 9, which is a single-digit number. Therefore, the statement is false.

(h) False

The smallest whole number is 0, not 1. 

(i) True

In the set of natural numbers, 1 is the smallest, so it has no predecessor.

(j) False

The predecessor of 1 in the set of whole numbers is 0.

(k) False

The number 13 is greater than 12, so it does not lie between 11 and 12.

(l) True

In the set of whole numbers, 0 is the smallest number and has no predecessor. 

(m) False

The successor of 99 is 100, which is a three-digit number. Therefore, the successor of a two-digit number is not always a two-digit number.