EXERCISE 2.1

1. Write the next three natural numbers after 10999.

The next three natural numbers after 10999 are found by adding 1 successively.

10999 + 1 = 11000

11000 + 1 = 11001

11001 + 1 = 11002

The next three natural numbers are 11000, 11001, and 11002.
Solution for question 1
2. Write the three whole numbers occurring just before 10001.

The three whole numbers just before 10001 are found by subtracting 1 successively.

10001 - 1 = 10000

10000 - 1 = 9999

9999 - 1 = 9998

The three whole numbers are 10000, 9999, and 9998.
Solution for question 2
3. Which is the smallest whole number?

Whole numbers are the set of natural numbers including zero.

The smallest whole number is 0.
4. How many whole numbers are there between 32 and 53?

The whole numbers between 32 and 53 are 33, 34, 35, ..., 52.

To find the count, we can use the formula: (Last Number - First Number) - 1

Count = \( (53 - 32) - 1 \)

Count = \( 21 - 1 \)

Count = 20

There are 20 whole numbers between 32 and 53.
5. Write the successor of :
(a) 2440701 (b) 100199 (c) 1099999 (d) 2345670

The successor of a number is the number that comes just after it. We find it by adding 1.

(a) Successor of 2440701 = \( 2440701 + 1 = 2440702 \)

(b) Successor of 100199 = \( 100199 + 1 = 100200 \)

(c) Successor of 1099999 = \( 1099999 + 1 = 1100000 \)

Solution for question 5c

(d) Successor of 2345670 = \( 2345670 + 1 = 2345671 \)

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

The predecessor of a number is the number that comes just before it. We find it by subtracting 1.

(a) Predecessor of 94 = \( 94 - 1 = 93 \)

(b) Predecessor of 10000 = \( 10000 - 1 = 9999 \)

Solution for question 6

(c) Predecessor of 208090 = \( 208090 - 1 = 208089 \)

(d) Predecessor of 7654321 = \( 7654321 - 1 = 7654320 \)

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

On a number line, the smaller number is always on the left of the greater number.

(a) 503 is to the left of 530. \( 503 < 530 \)

(b) 307 is to the left of 370. \( 307 < 370 \)

(c) 56789 is to the left of 98765. \( 56789 < 98765 \)

(d) 9830415 is to the left of 10023001. \( 9830415 < 10023001 \)

Solution for question 7
8. Which of the following statements are true True and which are false False ?

(a) Zero is the smallest natural number.

False

Explanation: The smallest natural number is 1. Natural numbers are counting numbers (1, 2, 3, ...).

(b) 400 is the predecessor of 399.

False

Explanation: The predecessor of a number is found by subtracting 1. The predecessor of 399 is 398. 400 is the successor of 399.

(c) Zero is the smallest whole number.

True

Explanation: Whole numbers include zero and all natural numbers (0, 1, 2, 3, ...).

(d) 600 is the successor of 599.

True

Explanation: The successor of a number is found by adding 1. The successor of 599 is 600.

(e) All natural numbers are whole numbers.

True

Explanation: The set of natural numbers (1, 2, 3, ...) is a part of the set of whole numbers (0, 1, 2, 3, ...).

False All whole numbers are natural numbers.

False

Explanation: The whole number 0 is not a natural number.

(g) The predecessor of a two digit number is never a single digit number.

False

Explanation: The predecessor of the two-digit number 10 is 9, which is a single-digit number.

(h) 1 is the smallest whole number.

False

Explanation: The smallest whole number is 0.

(i) The natural number 1 has no predecessor.

True

Explanation: Natural numbers start from 1, so there is no natural number before 1.

(j) The whole number 1 has no predecessor.

False

Explanation: The whole number 1 has a predecessor, which is 0.

(k) The whole number 13 lies between 11 and 12.

False

Explanation: The whole number 13 comes after 12.

(l) The whole number 0 has no predecessor.

True

Explanation: The whole number system starts with 0, so there is no whole number that comes before 0.

(m) The successor of a two digit number is always a two digit number.

False

Explanation: The successor of the two-digit number 99 is 100, which is a three-digit number.