# 8.05 Personal finance and percentages

Lesson

## Ideas

Can you  find a percentage of an amount  ?

### Examples

#### Example 1

What is 10\% of 60?

Worked Solution
Create a strategy

Use the fact that 10\% is equal to \dfrac{1}{10} and "of" means multiply.

Apply the idea
Idea summary

We can find a percentage of a quantity by converting the percentage to a fraction and multiplying by the quantity.

## Percentage discounts

How can we work out percentage discounts? In this video, we see how to do that, as well as work out the discounted price we need to pay.

### Examples

William is going to buy a jumper that is marked as 50\% off. The original price is \$96. a What is the value of the discount? Worked Solution Create a strategy 50\% of the price is the same as half the price. Apply the idea b What is the price that William will pay for the jumper? Worked Solution Create a strategy Subtract the discount from the original price. Apply the idea Idea summary To find the discount, multiply the original price by the percentage of the discount. To find the discounted price, subtract the discount from the original price. ## Goods and sales tax In Australia, Goods and Services Tax, or GST for short, is a 10\% tax that is charged on top of most things you buy. Let's learn more about calculating GST. Loading video... ### Examples #### Example 3 Joanne's bike cost \$90, excluding the 10\% goods and services tax (GST).

a

How much GST will Joanne get charged?

Worked Solution
Create a strategy

Find the 10\% of \\$90.

Apply the idea
b

What is the total amount Joanne pays for her bike?

Worked Solution
Create a strategy

We can use the formula: \text{Cost of items} + \text{GST} = \text{Total amount paid}

Apply the idea
Idea summary

In Australia, Goods and Services Tax (GST) is a 10\% tax on most things you buy. That means you pay an extra 10\% of the cost.

\text{Cost of items} + \text{GST} = \text{Total amount paid}

### Outcomes

#### VCMNA217

Make connections between equivalent fractions, decimals and percentages

#### VCMNA218

Investigate and calculate percentage discounts of 10%, 25% and 50% on sale items, with and without digital technologie