What Is a Number Line?

A number line is a straight line used to help us understand numbers and how they relate to each other.

Numbers increase as you move to the right, and decrease as you move to the left.

Number lines are helpful for visualising maths problems and understanding how numbers move when we add or subtract.

Example of a Number Line

Using a Number Line for Addition

Number lines are often used to help students add numbers.

Example:

3 + 2

Start at 3 and move two spaces to the right.

Answer = 5

Using a Number Line for Subtraction

Subtraction works the opposite way.

Example:

4 − 2

Start at 4 and move two spaces to the left.

Answer = 3

Why Number Lines Are Helpful

Number lines help children:

• understand number order
• visualise addition and subtraction
• develop strong number sense

They’re one of the most important tools in early maths learning.