What are negative numbers?

It's time for the next space shuttle launch. The countdown starts:

But what happens after lift off, after zero?

Let's look at another example, the weather. On a cold December night you can watch the thermometer as the temperature drops, as the numbers go down:
      2 degrees,  1 degree,  zero degrees
But what happens to the numbers if it gets even colder? The temperature and the numbers keep going down!

These numbers below zero are called negative numbers

We write negative numbers like this:
      negative 2 is the same as -2
The dash is the negative sign. It is usually written slightly shorter and a little higher up than a normal minus signs. But on the internet and in newspapers you will see it written using a minus sign.

Sometimes negative numbers are called minus numbers, careful you don't confuse these with subtraction.

Positive numbers

You already use positive numbers all the time! But, unlike negative numbers you don't have to put a + sign in front of them. Here are some examples of positive numbers:
      3,  46,  689,  1 982