NCERT Solution Exercise 2.1
Question (1) Write the next three natural numbers after 10999.
Answer
We can get the next number by adding 1 to a given number.
Thus, first natural number after 10999
= 10999 + 1 = 11000
And, the next natural number after 11000
= 11000 + 1 = 11001
And, the next natural number after 11001
= 11001 + 1 = 11002
Thus, next three natural numbers after 10999 are 11000, 11001, and 11002 Answer
Question (2) Write the three whole numbers occurring just before 10001.
Solution
We can get the number just before a given number by subtracting 1 from it.
Thus, the First whole number occurring just before 10001
= 10001 – 1 = 10000
And, the second whole number occurring just before 10000
= 10000 – 1 = 9999
And, the second whole number occurring just before 9999
= 9999 – 1 = 9998
Thus, the three whole numbers occurring just before 10001 = 10000, 9999, and 9998 Answer
Question (3) Which is the smallest whole number?
Answer
Zero (0) is the smallest whole number.
Explanation
Numbers start from 0 to infinity are called whole numbers.
In other words, natural numbers along with zero (0) are known as whole numbers.
This, means 0, 1, 2, 3, 4, 5, . . . . are whole numbers.
Thus, zero (0) is the smallest whole number. Answer
Question (4) How many whole numbers are there between 32 and 53?
Solution
We can get the numbers of whole numbers or natural numbers between given two numbers by subtracting the smaller from the greater.
Thus, number of numbers between 32 and 53
= 53 – 32 = 21
Thus, there are 21 whole numbers between 32 and 53. Answer
Question (5) Write the successor of
(a) 2440701
Solution
We can get the successor of a given number by adding 1 to it.
Thus, successor of 2440701
= 2440701 + 1 = 2440702
Thus, successor of 2440701 = 2440702 Answer
(b) 100199
Solution
We can get the successor of a given number by adding 1 to it.
Thus, successor of 100199
= 100199 + 1 = 100200
Thus, successor of 100199 = 100200 Answer
(c) 1099999
Solution
We can get the successor of a given number by adding 1 to it.
Thus, successor of 10,99,999
= 10,99,999 + 1 = 11,00,000
Thus, successor of 10,99,999 = 11,00,000 Answer
(d) 2345670
Solution
We can get the successor of a given number by adding 1 to it.
Thus, successor of 23,45,670
= 23,45,670 + 1 = 23,45,671
Thus, successor of 23,45,670 = 23,45,671 Answer
Question (6) Write the predecessor of:
(a) 94
Solution
We can get the predecessor of a given number by subtracting 1 from it.
Thus, the predecessor of 94
= 94 – 1 = 93
Thus, predecessor of 94 = 93 Answer
(b) 10000
Solution
We can get the predecessor of a given number by subtracting 1 from it.
Thus, the predecessor of 10,000
= 10,000 – 1 = 9,999
Thus, predecessor of 10000 = 9,999 Answer
(c) 208090
Solution
We can get the predecessor of a given number by subtracting 1 from it.
Thus, the predecessor of 20,80,90
= 20,80,90 – 1 = 20,80,89
Thus, predecessor of 20,80,90 = 20,80,89 Answer
(d) 7654321
Solution
We can get the predecessor of a given number by subtracting 1 from it.
Thus, the predecessor of 76,54,321
= 76,54,321 – 1 = 76,54,320
Thus, predecessor of 76,54,321 = 76,54,320 Answer
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 appropriate sign (>, <) between them.
(a) 530, 503
Answer
The smaller number lies to the left of a number on the number line.
Here, 503 is smaller than 530
Thus, 503 lies left to 530 on the number line and 530 > 503 Answer
(b) 370, 307
Answer
The smaller number lies to the left of a number on the number line.
Here, 307 is smaller than 370
Thus, 307 lies left to 370 on the number line and 370 > 307 Answer
(c) 98765, 56789
Answer
The smaller number lies to the left of a number on the number line.
Here, 56789 is smaller than 98765
Thus, 56789 lies left to 98765 on the number line and 98765 > 56789 Answer
(d) 9830415, 10023001
Answer
The smaller number lies to the left of a number on the number line.
Here, 9830415 is smaller than 10023001
Thus, 9830415 lies left to 10023001 on the number line and 9830415 > 10023001 Answer