Explore · Mathematics · Counting & Cardinality

How Many in Total?

Cardinality principle: the last number said when counting a set tells how many objects are in the set, regardless of arrangement or order counted

ages 4 to 68 practice questionsvideo included

What a learner can do afterwards

After counting a set, answer 'how many?' with the last number stated
Understand that rearranging objects does not change the count
Understand that counting in a different order gives the same total

The lesson

After you count, you already know how many there are. You do not need to count again. The last number you say is the total.

Tap each star and count out loud.

Count the stars: 1, 2, 3, 4, 5, 6. There are 6 stars in total.

Try it together

Mia lines up 5 apples and counts them: 5. Then she puts them in a pile. She does not need to count again. It is still 5 apples.

Tap each apple and count out loud.

Good to know

You can count in any order. Left to right or right to left, the total stays the same.

The last number you count is the total, no matter the order or the arrangement.

Watch it

Where it sits

Learn first

One-to-one counting

This opens up

Reading and writing numbers to 20 Sorting & Categorising Words Addition as combining or putting together two Representing numbers with objects One More Each Time Making Sense of Problems The teen numbers Sorting Data into Categories Counting objects to 20 Subtraction as taking away or separating

Then practise

8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.