Fractions, decimals and
percentages
• To be able to
convert fraction
to: Decimals and
percentages
• Must – be able to
convert a percentage
to and from a
decimal.
• Should – be able to
convert a fraction into
a percentage.
• Could – be able to
convert a percentage
into a fraction and
cancel it down.
Percentages
A percentage is just a special type of fraction.
1%
or
1
100
means
1 part per hundred
=
0.01
Percentages
A percentage is just a special type of fraction.
25%
or
25
100
means
=
25 parts per hundred
1
4
=
0.25
Percentages
A percentage is just a special type of fraction.
100% means 100 parts per hundred
or
100
100
=
1
Writing percentages as fractions
‘Per cent’ means ‘out of 100’.
To write a percentage as a fraction we write it over a hundred.
For example,
23
46
46% =
100
46
23
Cancelling:
=
100
50
180
180% =
100
180
9
=
=
Cancelling:
100
5
7.5
15
7.5% =
=
100
200
50
9
5
3
15
3
=
Cancelling:
200
40
40
1
4
5
Percentages into fractions
What is 26% as a fraction?
Percentages into fractions
What is 26% as a fraction?
26 = 13
100
50
Percentages into fractions
What is 162% as a fraction?
162 = 81 = 1 31
100
50
50
Writing percentages as decimals
We can write percentages as decimals by dividing by 100.
For example,
46
= 46 ÷ 100 = 0.46
46% =
100
7
= 7 ÷ 100 = 0.07
7% =
100
130
= 130 ÷ 100 = 1.3
130% =
100
0.2
= 0.2 ÷ 100 = 0.002
0.2% =
100
Percentages into decimals
What is 37% as a decimal?
Divide by 100 Move
Decimal to the left 2 times
Top Tip
37.
= .37
Percentages into decimals
What is 95% as a decimal?
Percentages into decimals
What is 113% as a decimal?
Writing fractions as percentages
To write a fraction as a percentage, we can find an equivalent
fraction with a denominator of 100.
For example,
×5
17
20
85
=
100
×5
and
85
= 85%
100
×4
7
25
=
×4
28
100
and
28
= 28%
100
Writing decimals as percentages
To write a decimal as a percentage you can multiply it
by 100%.
For example,
0.08 = 0.08 × 100%
= 8%
1.375 = 1.375 × 100%
= 137.5%
Writing fractions as percentages
To write a fraction as a percentage, we can find an equivalent
fraction with a denominator of 100.
For example,
×5
11
20
55
=
100
×5
and
55
= 55%
100
× 10
6
10
=
60
100
× 10
and
60
= 60%
100
Converting equivalents
Let’s fill in the
gaps in this
table
…
Check your answers
Answers
Answers
Table of equivalences Plenary
Dominoes