year 8 maths

4F
Converting fractions, decimals and percentages
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4F Converting fractions, decimals and percentages
REVISION
Per cent is Latin for ‘out of 100 ’. One dollar equals 100 cents and one century equals 100 years.
We come across percentages in many everyday situations. Interest rates, discounts, test results and
statistics are just some of the common ways we deal with percentages.
Percentages are closely related to fractions. A percentage is another way of writing a fraction with a
denominator of 100 . Therefore, 63% means that if something is broken into 100 parts you would have
63 of them (i.e. 63% = 63
100 ).
Let’s start: Estimating percentages
Creamy
soda
Lime
Orange
Cola
Lemon Milkshake Raspberry Chocolate
• Estimate the percentage of drink remaining in each of the glasses shown above.
• Discuss your estimations with a partner.
• Estimate what percentage of the rectangle below has been shaded in.
• Use a ruler to draw several 10 cm × 2 cm rectangles. Work out an amount you would like to shade in,
then use your ruler to measure precisely the amount to shade. Shade in this amount.
• Ask your partner to guess the percentage you shaded.
• Have several attempts with your partner and see if your estimation skills improve.
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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