## 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**