Different Types of Numbers

Cardinal numbers are counting numbers. Ordinal numbers tell us about position. Nominal numbers are just names: they don't have any value or position.

Cardinal numbers

The cardinal numbers are the counting numbers. They are whole numbers that tell you how many of something there are. So, they don't include fractions or decimals. For example, you would use a cardinal number to describe the number of brussels sprouts that are on your plate at the start of dinner (hopefully, \(0\)!). In the picture below, there are six coins. Six is a cardinal number.

Ordinal Numbers

How do we describe the position of something in a race, a line or a list? Using an ordinal number. Ordinal numbers tell us about position. They are things like 1st (or first), 2nd(or second), 3rd (or third) 4th (or fourth), 5th (or fifth) and 6th (or sixth), etc. For example, the snails in the picture below are having a race.

The pink and purple snail is winning, so he is in 1st position. The green and yellow snail is coming second, the red and brown snail is coming third and the brown and yellow snail is coming last. As there are only four snails in the race, he is in 4th position.

Nominal Numbers

These are just numbers that are used as names. For example, the car in the picture below is given the number \(453\) as a name. This name tells us nothing about how many cars there are or the position of the car in a race.

Some other examples of nominal numbers include

• The number on a cricketer's shirt. Nathan Lyon wore shirt number 67 in 2016.
• A post code: Melbourne's post code is 3000.
• A lego set number such as 75192.

Nominal numbers let us name things.