The Lesson

A number line is line where every point corresponds to a number.The numbers are evenly spaced. Numbers get larger as you move right and smaller as you move left along the line. The number line can go on left and right forever.

Dictionary Definition

The Oxford English Dictionary defines a number line as "a graduated line representing the ordered set of real numbers (sometimes only the set of integers or natural numbers), used especially to illustrate simple numerical concepts and operations."

Numbers on a Number Line

Numbers can be found on a number line.
  • Numbers can be positive and negative numbers and zero.
  • We can find integers on the number line, such as −3, 0 and 2.
  • We can find fractions and decimals on the number line, such as −2.5 and 1⁄2.They are found in between the integers.

Ordering of Numbers

Numbers get larger as you move right and smaller as you move left along the line.This means that:
  • any number is greater than any number to its left.
  • any number is less than any number to its right.
For example,
  • 3 is greater than 1.
  • −1 is less than 1.

The Direction of the Number Line

We have drawn the number line horizontally:

A number line could be drawn vertically: