More on comparing size of integers

Integers can be represented as equally spaced points on a number line. The horizontal number line is drawn below.

Number Line

Did you notice that the numbers to the left of zero have negative signs in front of them?

Important

Numbers to the right of zero are called 'positive' numbers: $+1, +2, +3, +4$, and so on. We don't usually write or say the positive sign, unless it's really needed to communicate clearly.

Numbers to the left of zero are called 'negative' numbers: $-1, -2, -3, -4$, and so on. We always write and say the negative sign $(-)$ to communicate clearly.

The number zero is neither negative nor positive.

Example

Examples where negative integers are used include temperatures below zero degrees, money transactions where you owe more than you receive, moving in a backward direction, elevations below sea level, and golf scores below par.

A temperature of $-15$ degrees Celsius is colder than a temperature of $-3$ degrees Celsius. So $-15$ is more negative, and so smaller than, $-3$.

Important

When comparing the size of two integers think about where they are on the number line:

  • we say the number furthest to the right is largest
  • we say the number furthest to the left is smallest.

So:

  • $1$ is greater than $-2$, also written as $1 \gt -2$. On the number line $1$ is to the right of $-2$.
  • $-3$ is smaller than $-1$, also written as $-3 \lt -1$. On the number line $-3$ is to the left of $-1$.
It is important that you can compare integers and be able to say which integer is bigger or smaller than another. Do you know how to do this?
Is $-3$ greater than $2$?
Is $-2$ smaller than $-1$?