# Describing arrays

## Learning focus

Learn how to use an array to see the commutativity of multiplication facts (for example 3 x 5 is the same as 5 x 3).

This lesson includes:

- two videos
- three activities

# Learn

### Repeated addition and multiplication: Describing arrays

Watch this animation from 1st Level Maths and Numeracy. Fin and Snoot count Meebs by putting them into equal rows and columns.

## What is an array?

An **array** is a way of representing multiplication facts in a diagram or picture. It is always rectangular and made up of **rows** and **columns.**

An array is helpful for calculating multiplication statements, for example, 2 x 4 which can be shown using this array:

There are 2 rows of apples and 4 apples in each

**row.**There are 4 columns of apples and 2 apples in each

**column.**

This array shows the multiplication statements 2 x 4 and 4 x 2.

The array has 8 apples in total. This tells us that 2 x 4 and 4 x 2 are both equal to 8.

*2 x 4 = 8* and *4 x 2 = 8*

## Example 1:

Here is an array to show a multiplication fact:

There are 3 rows of sweets and 5 sweets in each

**row.**There are 5 columns of sweets and 3 sweets in each

**column.**

This array shows the multiplication statements 3 x 5 and 5 x 3.

The array has 15 apples in total. This tells us that 3 x 5 and 5 x 3 are both equal to 15.

*3 x 5 = 15* and *5 x 3 = 15*

## Top tip

Remember multiplication is **commutative.**

4 x 3 is the same amount as 3 x 4.

4 **lots of** 3 is the same amount as 3 **lots of** 4.

## Example 2:

Here is an array to show 6 x 2

Can you see 6 lots of 2?

Can you see 2 lots of 6?

How many footballs are there in the array?

This array shows that *6 x 2 = 2 x 6*.

Now let's recap with this video from KS1 Maths. Can you think how you might show 3 x 7 using an array?

# Practise

## Activity 1

Can you draw an array to show 3 x 4?

Which other multiplication fact does it show?

Does it help you calculate 4 x 3?

### Remember

An **array** is a rectangular diagram to show a multiplication fact. It always has **rows** and **columns** and shows that multiplication is **commutative.**

## Activity 2

**Make an array activity**

Try this interactive activity to see if you can answer the question by making your own array.

## Activity 3

**Worksheet: Using arrays**

This worksheet from Classroom Secrets Kids contains **three** tasks about using arrays. Have a go and see if you can get them all correct.

Finished? Check here for the answer sheet

# Play

Test your skills on this topic even further by playing **Karate Cats Maths** - see if you can collect a new costume for your cat!

# There's more to learn

Have a look at these other resources.