year 8 maths

248 Chapter 4 Fractions, decimals, percentages and financial mathematics
4I The Goods and Services Tax (GST)
The Goods and Services Tax or GST is a broad-based tax on most goods and services sold or consumed in
Australia.
The advertised price of the goods in shops, restaurants and other businesses must include the GST. At
present in Australia the GST is set at 10% .
Not all goods and services are taxed under the GST. Items that are exempt from the goods and services
tax include: most basic foods, some education courses and some medical and healthcare products and
services.
Let’s start: GST
Look at the prices before and after GST is included.
Before
GST
$180
×
After
GST
$198
• How much GST was paid?
• What percentage is the GST?
• What number could be placed in the box?
• If the GST was 12% , what number would go in the box?
Key ideas
■ The GST is 10% of the usual sale price. It is paid by the consumer and passed onto the
government by the supplier.
■ The final advertised price, inclusive of the GST, represents 110% of the value of the product:
the cost (100%) plus the GST of 10% gives 110% .
■ The unitary method can be used to find the GST included in the price of an item or the pre-tax
price.
It involves finding the value of ‘one unit’, usually 1% , then using this information to answer the
question.
■ Alternatively, this chart could be used:
Before
GST
(100%)
× 1.1
÷ 1.1
After
GST
(110%)
For example:
× 1.1
$120 $132
÷ 1.1
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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