Page 77 - Mathematics Coursebook

7.2 Recognising equivalent fractions, decimals and percentages

Percentages can be written as fractions with a denominator of 100, as the
14
words ‘per cent’ mean ‘out of 100’. 8% = 100 , 14% = 100
8
You need to be able to recognise equivalent fractions, decimals and
percentages.

!e diagram shows the ones that are most commonly used.
Learn these and it will help you answer all sorts of questions in the future!

0.25 0.5 0.75
0 0.1 0.2 0.3 0.4 0.6 0.7 0.8 0.9 1

1 1 1 3 2 1 3 7 3 4 9
0 1
10 5 4 10 5 2 5 10 4 5 10

0 10% 20% 30% 40% 60% 70% 80% 90% 100%
25% 50% 75%

Worked example 7.2B

a Write the following percentages as fractions. i 5% ii 83%
b Write 20% as: i a fraction ii a decimal.

5
a i 5% = 100 5 per cent means 5 out of 100.
5 1 5
100 = 20 100 can be cancelled by dividing 5 and 100 by 5.
83 83
ii 83% = 100 83 per cent means 83 out of 100 100 cannot be cancelled.

20
1
B i 20% = 1 20% is a commonly used percentage, 20% as a fraction is 100 = .
5
5
ii 20% = 0.2 20% as a decimal is 0.2.
) Exercise 7.2

1 Write these decimal numbers as fractions in their simplest form.
a 0.3 b 0.9 c 0.2 d 0.6 e 0.8
f 0.17 g 0.35 h 0.84 i 0.07 j 0.04
k 0.139 l 0.125 m 0.826 n 0.042 o 0.006

2 Write these percentages as fractions.
a 9% b 27% c 81% d 69% e 11%

76 7 Fractions