Page 74 - MAT KS3 Y8 Cambridge CheckPoint

7.1 Finding equivalent fractions, decimals and percentages

Worked example 7.1b
3
Write: a 32% as a fraction b 20 as a percentage.
32
a 32% = 100 First, write 32% as a fraction with a denominator of 100.
÷
32 4 8
= Cancel the fraction to its lowest terms.
÷
100 4 25
×
35 15 3
b = First, write as an equivalent fraction with a denominator of 100.
×
20 5 100 20
15 15
= 15% You can either say that is ‘15 out of 100’ so is 15%, or you can change
100 100
15
100 into the decimal 0.15, then multiply by 100 to get 15%.
✦ Exercise 7.1

1 Use the numbers from the box to complete these sentences.
You can only use each number once.

7 1 1 1
.
.
.
06 04 10 75% 4 80% 5 075 2

a 0.25 = b 40% = c 4 = d 50% =
5
e 60% = f 0.2 = g 0.7 = h =
2 Write each percentage as: i a decimal ii a fraction.
a 14% b 74% c 24% d 8%
3 Write each decimal as: i a percentage ii a fraction.
a 0.34 b 0.06 c 0.68 d 0.81
4 Write each fraction as: i a decimal ii a percentage.

a 9 b 7 c 1 d 19
25 20 25 20
5 This is part of Harsha’s homework.
Use Harsha’s method to write these
fractions as percentages. Question Write these fractions as
percentages.
a 1 b 7 c 3
7
8 8 40 a 3 b 40
8
d 19 e 4 f 67
40 125 125 3 125 375 375
×
A A A A A A A A
,
.
×
g 51 h 3 i 133 Answer a 8 125 = 1000 1000 = 0 375
200 200 200
0.375 × 100 = 37.5%
j 471 k 17 l 9
500 500 500 725 175 175
×
,
0 175
b 40 25 = 1000 1000 = .
×
0.175 × 100 = 17.5%
72 7 Fractions