Cardinal and Ordinal Numbers

Lesson Plan - Get It!

Audio:

Cardinal numbers tell how many, and ordinal numbers tell position.

A cardinal number tells how many of something there are, such as 2 cats or 5 dogs. It answers the question, "How many?" Cardinal numbers are only used for counting, so fractions and decimals are not used.

• In the picture below, how many children are jumping?

There are 4 children. Four is a cardinal number. We can count how many children there are.

Remember, ''Cardinal is for Counting!''

Another type of number is called an ordinal number. Ordinal numbers tell the position of something in a list, like first, second, third, or tenth. They tell what order things are in. Ordinal numbers are also used to name the rank of something, like first in line or fourth place.

Look at the picture below and discuss with a parent or teacher:

• In this picture, what position is the boy in the green shirt?
• What position is the girl reading the book?

The boy in the green shirt is first in line. The girl reading the book is fourth in line. These are examples of ordinal numbers!

Ordinal numbers are used to tell the position of objects placed in a particular order. If seven people ran a race, the fastest person was in first place, the next person was in second place, and the slowest person was in seventh place. Normally, a special ending is added to the end of a number, such as "th," "nd," or "st."

Remember, "Ordinal is for Ordering."

Before you move on to look at the difference between cardinal and ordinal numbers, take a moment to view the Ordinal Numbers Song, from Mr. R.'s Songs for Teaching:

Now, read through this table of the first ten ordinal and cardinal numbers:

Discuss the questions below with another person:

• What do you notice about the way you read the first two ordinal numbers?
• In a race, is it better to be first or fifth? Explain your answer.
• When are cardinal numbers used?
• When are ordinal numbers used?

Now that you know the difference between cardinal and ordinal numbers, move on to the Got It? section to practice by playing a few games!