Ordinal numbers

What are ordinal numbers?

Ordinals numbers tell you what position something is in.

You often use them to rank or order things.

Most ordinal numbers end with a 'th' sound, like 'fourth' or 'fifth'. However, they can also end with a 'st', 'nd' or 'rd'.

You can write ordinal numbers as words or with a number and the matching sound.

Quiz: Ordinal numbers

Take this quiz to see how much you know about ordinal numbers already. Then complete the guide and see if you can beat your score.

Ordering numbers

Betty wants to build a staircase pattern using some colourful blocks.

What do you notice about the order she has put the blocks in?

Betty has not put them in the right order.

Let’s put them in the right order now.

Can you see that when the numbers are in the right order they make a staircase pattern.

Why do you think this is?

The number that comes after a number is one more and the number that comes before a number is one less.

Now that they are in the right order, we can use ordinal numbers to describe them.

Let’s label the blocks using the different ordinal numbers.

Everyday ordinal numbers

You probably use ordinal numbers quite a lot without realising it.

Here are some examples.

Example 1

Let's practise using ordinal numbers.

Here is a line up of different animals.