Class 6 Maths Chapter 2 Whole Numbers – Best Explanation | Properties, Examples & Worksheets

Key Learning Outcomes

By the end of this chapter, “Whole Numbers”, readers will:

• Definition of whole numbers
• Whole numbers on a number line
• Properties of whole numbers
• Successor and predecessor
• Patterns in whole numbers

Introduction

Whole numbers are one of the most important concepts in mathematics. Students learn about whole numbers in Class 6 Mathematics because they form the foundation of many mathematical operations.

Understanding whole numbers helps students improve their problem-solving and calculation skills.

Let’s understand these concepts in a fun and simple way!

What Are Whole Numbers?

Whole numbers are numbers starting from 0 and continuing endlessly without fractions or decimals.

Definition

Whole numbers are the set of numbers:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 …

These numbers are used for counting objects.

Example:

0
1
2
3
4
5
6
7
8
9
10 etc.

Difference Between Natural Numbers and Whole Numbers

Natural Numbers	Whole Numbers
Start from 1	Start from 0
1, 2, 3, 4…	0, 1, 2, 3, 4…

Important Point: All natural numbers are whole numbers, but 0 is only included in whole numbers.

Whole Numbers on a Number Line

A number line helps us visualize numbers.

Example:

0 — 1 — 2 — 3 — 4 — 5 — 6 — 7 — 8 — 9 — 10

Important observations:

1. Numbers increase when we move right.
2. Numbers decrease when we move left.

Successor and Predecessor

Successor:

The number that comes after a given number is called its successor.

Example:

Successor of 5 = 6
Successor of 20 = 21

Formula:

Successor = Number + 1

Predecessor:

The number that comes before a given number is called its predecessor.

Example:

Predecessor of 7 = 6
Predecessor of 50 = 49

Formula:

Predecessor = Number − 1.

Properties of Whole Numbers

Whole numbers follow several important properties.

1. Closure Property:

When we add or multiply two whole numbers, the result is always a whole number.

Example:

5 + 7 = 12
4 × 6 = 24

However, subtraction and division do not always give whole numbers.

Example:

5 − 8 = −3 (not a whole number)

2. Commutative Property:

Changing the order of numbers does not change the result.

a. Addition

4 + 6 = 6 + 4

b. Multiplication

3 × 5 = 5 × 3

Subtraction does not follow this property.

Example:

7 − 3 ≠ 3 − 7

3. Associative Property:

Changing the grouping of numbers does not change the result.

Example:

(2 + 3) + 4 = 2 + (3 + 4)

Multiplication also follows the associative property.

Example:

(2 × 3) × 4 = 2 × (3 × 4)

4. Identity Property:

Identity elements do not change the value of numbers.

Additive Identity

0 is the additive identity.

Example:

8 + 0 = 8

Multiplicative Identity

1 is the multiplicative identity.

Example:

8 × 1 = 8

5. Distributive Property:

Multiplication distributes over addition.

Example:

3 × (4 + 2)

= 3 × 6
= 18

OR

(3 × 4) + (3 × 2)

= 12 + 6
= 18

Patterns in Whole Numbers

Whole numbers form many patterns.

Even Numbers

Numbers divisible by 2.

Example:

2, 4, 6, 8, 10

Odd Numbers

Numbers not divisible by 2.

Example:

1, 3, 5, 7, 9

Importance of Whole Numbers in Daily Life

Whole numbers are used in everyday activities.

Examples:

• Counting students in a class
• Counting money
• Calculating scores
• Measuring distances

Example:

A classroom has 40 students.

The number 40 is a whole number.

Important Facts

1. Whole numbers start from 0
2. They do not include negative numbers
3. They do not include fractions or decimals
4. Whole numbers are infinite
5. Every number has a successor
6. Every number except 0 has a predecessor
7. All Natural Numbers Are Whole Numbers (Natural Numbers ⊂ Whole Numbers)
8. Whole Numbers Can Be Represented on a Number Line
9. Addition of Whole Numbers Always Gives a Whole Number
10. Multiplication of Whole Numbers Always Gives a Whole Number
11. Subtraction of Whole Numbers May Not Give a Whole Number
12. Division of Whole Numbers May Not Give a Whole Number
13. 0 is the Additive Identity
14. 1 is the Multiplicative Identity

Practice Questions:

A: Fill in the Blanks

1. The smallest whole number is ______.
2. The successor of 45 is ______.
3. The predecessor of 100 is ______.
4. Whole numbers start from ______.
5. Whole numbers do not include ______ numbers.

Answers

1. 0
2. 46
3. 99
4. 0
5. negative

B: True or False

1. 0 is a whole number.
2. Whole numbers include negative numbers.
3. Whole numbers can be represented on a number line.
4. 1 is the smallest whole number.
5. Whole numbers include fractions.

Answers

1. True
2. False
3. True
4. False
5. False

C: Short Answer Questions

1. Write the first 10 whole numbers.
2. Find the successor of the following numbers: a) 9 b) 25 c) 67
3. Find the predecessor of the following numbers: a) 12 b) 50 c) 200

Answers

1. 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
2. a) 10 b) 26 c) 68
3. a) 11 b) 49 c) 199

D: Solve the Following

1. 35 + 24 = ______
2. 48 − 16 = ______
3. 9 × 7 = ______
4. 56 ÷ 8 = ______
5. 72 − 28 = ______

Answers

1. 59
2. 32
3. 63
4. 7
5. 44

E: Word Problems

1. A school library has 245 books. The school bought 35 more books. How many books are there now?
2. A farmer collected 96 mangoes. He sold 28 mangoes. How many mangoes are left?
3. A shopkeeper has 8 boxes. Each box contains 12 pencils. How many pencils are there in total?

Answers

1. 245 + 35 = 280 books
2. 96 − 28 = 68 mangoes
3. 8 × 12 = 96 pencils

F: Challenge Questions

1. Write the whole number that comes between 99 and 101.
2. What will you get if you add 0 to any whole number?
3. What is the successor of 999?

Answers

1. 100
2. The same number
3. 1000

Supplementary Materials:

Provide downloadable materials for learners to review:

• – PDF Guide: “Coming Soon”
• – Cheat Sheet: “Coming Soon”
• – Video Source: “JNG ACADEMY“
• – Articles: “Blog Page“

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