Number Line Class 6 ICSE — Maths Chapter 3

Written by Greya LakshmiPublished on 14 October 2026

The number line class 6 ICSE chapter, Chapter 3 of the Class 6 Mathematics book, explains how to draw a number line and use it to compare, add and subtract integers. For syllabus details, visit the official CISCE website. You will learn the drawing steps, the difference between natural, whole and integer number lines, and the direction rules that fix your answer. This ICSE chapter covers integers only, not fractions or roots.

Download Number Line Class 6 ICSE Mathematics Chapter 3 PDF

Download the Number Line Class 6 ICSE Mathematics chapter PDF to revise offline or print for practice. It is the full chapter as printed in the book — 6 pages, 4 sections, 16 questions.

What is inside Chapter 3

6 pages · 4 sections · 8 worked examples · 16 exercise questions

Section	Title
3.1	NUMBER LINE
3.2	NUMBER LINES FOR NATURAL NUMBERS, WHOLE NUMBERS AND INTEGERS
3.3	USING A NUMBER LINE TO COMPARE NUMBERS
3.4	USING A NUMBER LINE

EXERCISE 3(A): 7 questions
EXERCISE 3(B): 5 questions
Revision Exercise (Chapter 3): 4 questions

3.1 NUMBER LINE

A number line is a straight line that can represent all real numbers, such as $-23, 0, 8, \frac{3}{5}, 2\frac{1}{5}, \sqrt{2}$ and $\sqrt{5}$ . Of these, $-23, 0$ and $8$ are integers, while the rest are non-integers. In this chapter, the number line is used for integers only, not for fractions or roots.

This section is part of the Class 6 Maths book, which builds the idea step by step. To draw a number line, follow these four steps:

Draw a straight line of any suitable length.
Mark points on the line to divide it into the required number of equal parts.
Mark the centre point of the line as zero.
Starting from zero, mark the positive integers $+1, +2, +3$ on the right and the negative integers $-1, -2, -3$ on the left.

Here is the pattern in action. Suppose you need a line from $-4$ to $+4$ . Draw the line, divide it into eight equal parts, mark zero at the centre, then place $+1, +2, +3, +4$ to the right and $-1, -2, -3, -4$ to the left.

Arrow-heads at the two ends of the line show that the line, and the integers on it, continue up to infinity on both the positive and negative sides.

3.2 NUMBER LINES FOR NATURAL NUMBERS, WHOLE NUMBERS AND INTEGERS

A number line for natural numbers starts from 1 and marks 2, 3, 4, 5 at equal distances to the right. The arrow-head on the right shows that the natural numbers continue up to infinity.

A number line for whole numbers starts from 0 and marks 1, 2, 3, 4 at equal distances to the right. It too has one arrow-head on the right.

Integers form the set $\{..., -3, -2, -1, 0, 1, 2, 3, 4,... \}$ . On the integer line, zero is marked anywhere on the line, with positive numbers to its right and negative numbers to its left at the same equal distances. This line alone has arrow-heads on both sides.

Number type	Starting point	Arrow-heads	Example set
Natural numbers	1	Right side only	$\{1, 2, 3, 4, 5, 6,...\}$
Whole numbers	0	Right side only	$\{0, 1, 2, 3, 4, 5,...\}$
Integers	0 at any point	Both sides	$\{..., -4, -3, -2, -1, 0, 1, 2, 3, 4, 5,...\}$

Whatever the set, the distance between any two consecutive numbers is always the same. That equal spacing is why you can count steps on the line reliably. This idea carries into the rest of the Class 6 ICSE syllabus as you compare and compute with integers.

3.3 USING A NUMBER LINE TO COMPARE NUMBERS

Out of any two numbers marked on a number line, the number to the right is greater and the number to the left is smaller. So each number is greater than every number to its left and smaller than every number to its right.

Three summary points follow from this rule. Every positive number is greater than every negative number. Zero is smaller than every positive number but greater than every negative number. The greater a number is, the smaller its opposite.

The symbol $\lt$ means ‘is less than’ and $\gt$ means ‘is greater than’. For example, since $8 \gt 5$ , the opposite comparison gives $-8 \lt -5$ . Similarly, since $6 \lt 7$ , it follows that $-6 \gt -7$ . If you need a refresher on integer basics, the earlier chapter on integers covers them.

Here is a worked pattern with original numbers. Mark the integers $-5, 4, -1, 0, 6, -3$ on a line. Ascending order, from smaller to greater, is $-5, -3, -1, 0, 4, 6$ , written as $-5 \lt -3 \lt -1 \lt 0 \lt 4 \lt 6$ . Descending order is $6, 4, 0, -1, -3, -5$ , written as $6 \gt 4 \gt 0 \gt -1 \gt -3 \gt -5$ .

A common mistake is to treat more negative numbers as bigger, because ‘more’ sounds larger. On a number line the opposite is true. The farther left a number sits, the smaller it is, so $-8$ is smaller than $-3$ .

3.4 USING A NUMBER LINE

A number line can also do addition and subtraction. For addition, treat each number as a movement from zero. A positive number moves you right, and a negative number moves you left.

The four addition cases are: positive plus positive moves right twice; positive plus negative moves right then left; negative plus positive moves left then right; negative plus negative moves left twice.

Worked pattern: evaluate $(-3) + (+5)$ . Start from zero and move 3 units left for $-3$ , then move 5 units right for $+5$ . You reach $+2$ , so $(-3) + (+5) = +2$ .

For subtraction, mark both numbers on the same line, each starting from zero. Count the steps needed to reach the first number from the position of the number being subtracted. If the steps move towards the right, the answer is a positive number; if they move towards the left, the answer is a negative number.

Worked pattern: evaluate $(+4) - (+1)$ . From the position of $+1$ , you need 3 steps to the right to reach $+4$ , so $(+4) - (+1) = +3$ . Evaluate $(+3) - (-2)$ . From $-2$ , you move 5 steps to the right to reach $+3$ , so $(+3) - (-2) = +5$ .

This ICSE chapter’s edge case surprises many students: subtracting a negative number moves you towards the right and gives a positive result. Evaluate $(-5) - (+3)$ . From the position of $+3$ , you need 8 steps to the left to reach $-5$ , so $(-5) - (+3) = -8$ .

What to practise from this chapter

This ICSE chapter gives you three practice blocks. Work through them in order after you finish the section they follow.

EXERCISE 3(A) — 7 questions on comparing and ordering integers using a number line.
EXERCISE 3(B) — 5 questions on addition and subtraction using a number line.
Revision Exercise (Chapter 3) — 4 questions covering the whole chapter.

Frequently asked questions

How do I draw a number line for class 6 ICSE maths?

Draw a straight line of suitable length and divide it into equal parts. Mark zero at the centre, then place $+1, +2, +3$ to the right and $-1, -2, -3$ to the left. Add arrow-heads at both ends.

On a number line, which integer is greater — the one on the right or the one on the left?

The one on the right. Out of any two marked numbers, the number to the right is always greater and the number to the left is always smaller.

How do I use a number line to subtract one integer from another?

Mark both numbers on the same line, starting each from zero. Count the steps from the number being subtracted to the other number. Steps to the right give a positive answer; steps to the left give a negative answer.

Why is every positive number greater than every negative number?

Every positive number sits to the right of zero, and every negative number sits to the left of zero. Since right means greater, every positive number beats every negative number.

How are natural numbers, whole numbers and integers different on a number line?

Natural numbers start at 1, whole numbers start at 0, and integers extend to both sides of zero. Natural and whole number lines have one arrow-head on the right, while the integer line has arrow-heads on both sides. The spacing between consecutive numbers is always equal.

Reference: ICSE Class 6 Mathematics textbook material, chapter 3: Number Line — CISCE-aligned.

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