# 6.11 Multiplication by 6

Lesson

## Ideas

Multiplication looks at equally sized groups. Can you solve this problem?

### Examples

#### Example 1

Find the value of 3\times 9.

Worked Solution
Create a strategy

We can think of 3 \times 9 as 3 groups of 9 like in the image below that has 3 groups of 9 squares:

Apply the idea

The above image has 27 squares in total.

Idea summary

Multiplying by three is the same as tripling and can be thought of as the total of three equally sized groups.

## Multiply numbers by 6

Let's look at how to multiply numbers by 6.

### Examples

#### Example 2

Find the value of 6\times3.

Worked Solution
Create a strategy

We can think of 6\times 3 as 6 groups of 3 just like in the image below that has 6 groups of 3 squares:

Apply the idea

The above image has 18 squares in total.

6 \times 3 = 18

Reflect and check

We can also multiply the number by 3 then double the answer:

Idea summary

You can use a doubling strategy to multiply a number by 6. Start by multiplying the number by 3, then double the answer.

### Outcomes

#### MA2-6NA

uses mental and informal written strategies for multiplication and division