How to start…
Write the following in full to 9 decimal places…
a) 0.6
b) 0.53
c) 0.72
d) 0.479
e) 0.328
●
●
● ●
● ●
● ●
How to start…
Write the following in full to 9 decimal places…
a) 0.6
b) 0.53
c) 0.72
d) 0.479
e) 0.328
●
●
● ●
● ●
● ●
→ 0.666666667
→ 0.533333333
→ 0.727272727
→ 0.479479479
→ 0.328282828
How do we convert
recurring decimals to
fractions?
To convert
fractions to
decimals
To convert a
recurring
decimal to a
fraction
Fraction to decimal
How do we change a
fraction to a
decimal?
Fraction to decimal
We divide the
numerator by the
denominator.
Fraction to decimal
e.g.
1
8
= 1 ÷ 8 =
8 1
Fraction to decimal
e.g.
1
8
= 1 ÷ 8 =
8 1. 0 0 0
0.1 2 5
Fraction to decimal
Sometimes the decimal will be a recurring decimal
3 1. 0 0 0
e.g.
1
3
= 1 ÷ 3 =
Fraction to decimal
Sometimes the decimal will be a recurring decimal
3 1. 0 0 0
0.3 3 3
e.g.
1
3
= 1 ÷ 3 = Because the same
division is repeating
over and over we can
say it is recurring. The
digits which recur are
marked with a dot
above them.
Fraction to decimal
Sometimes the decimal will be a recurring decimal
3 1. 0 0 0
0.3 3 3
e.g.
1
3
= 1 ÷ 3 = Because the same
division is repeating
over and over we can
say it is recurring. The
digits which recur are
marked with a dot
above them.
1
3
= 0. 3
Fraction to decimal
Fraction to decimal
11 3. 0 0 0 0
0.2 7 2 7
Fraction to decimal
11 3. 0 0 0 0
0.2 7 2 7 3
11
= 0. 27
Fraction to decimal
Change
5
6
into a decimal.
Fraction to decimal
6 5. 0 0 0 0
0. 8 3 3 3 5
6
= 0. 83
Change
5
6
into a decimal.
Notice only the 3 has a dot over it
as only the 3 recurs.
Fraction to decimal
Change these fractions into decimals.
1.
7
11
2.
8
9
3.
12
9
Fraction to decimal
Change these fractions into decimals.
1.
7
11
2.
8
9
3.
12
9
= 0. 63
Fraction to decimal
Change these fractions into decimals.
1.
7
11
2.
8
9
3.
12
9
= 0. 63
= 0. 8
Fraction to decimal
Change these fractions into decimals.
1.
7
11
2.
8
9
3.
12
9
= 0. 63
= 0. 8
= 1. 3
To convert
fractions to
decimals
To convert a
recurring
decimal to a
fraction
To convert
fractions to
decimals
To convert a
recurring
decimal to a
fraction
The algebra of
recurring decimals
What is a recurring
decimal?
The algebra of
recurring decimals
A decimal where the
digit(s) repeat.
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
The algebra of
recurring decimals
Check this on a calculator by dividing 4 by 9.
Let’s change 0.7 into a fraction
The algebra of
recurring decimals
Let x= 0.7 so
. .
Let’s change 0.7 into a fraction
The algebra of
recurring decimals
Let x= 0.7 so 10x = 7.7
. .
Let’s change 0.7 into a fraction
Multiply!
The algebra of
recurring decimals
Let x= 0.7 so 10x = 7.7
. .
10x= 7.7777777777777777...
x= 0.7777777777777777...
Let’s change 0.7 into a fraction
Multiply!
Subtract!
The algebra of
recurring decimals
Let x= 0.7 so 10x = 7.7
. .
10x= 7.7777777777777777...
x= 0.7777777777777777...
9x=7
Let’s change 0.7 into a fraction
Multiply!
Subtract!
The algebra of
recurring decimals
Let x= 0.7 so 10x = 7.7
. .
10x= 7.7777777777777777...
x= 0.7777777777777777...
9x=
x= 7
9
Let’s change 0.7 into a fraction
Multiply!
Subtract!
Divide!
The algebra of
recurring decimals
7
Change 0.47 into a fraction
. .
The algebra of
recurring decimals
Change 0.47 into a fraction
. .
Let x= 0.47
. .
The algebra of
recurring decimals
Change 0.47 into a fraction
. .
Let x= 0.47
. .
Multiply!
The algebra of
recurring decimals
With what
this time?
Change 0.47 into a fraction
. .
Let x= 0.47
. .
Multiply!
The algebra of
recurring decimals
With 100
Change 0.47 into a fraction
. .
Let x= 0.47
. .
so 100x = 47.47
. .
Multiply!
The algebra of
recurring decimals
Change 0.47 into a fraction
. .
Let x= 0.47
100x= 47.4747474747474747...
x= 0.4747474747474747...
. .
so 100x = 47.47
. .
Multiply!
Subtract!
The algebra of
recurring decimals
Change 0.47 into a fraction
. .
Let x= 0.47
100x= 47.4747474747474747...
x= 0.4747474747474747...
. .
so 100x = 47.47
. .
Multiply!
Subtract!
The algebra of
recurring decimals
Change 0.47 into a fraction
. .
Let x= 0.47
100x= 47.4747474747474747...
x= 0.4747474747474747...
99x= 47
. .
so 100x = 47.47
. .
Multiply!
Subtract!
Divide!
The algebra of
recurring decimals
Change 0.47 into a fraction
. .
Let x= 0.47
100x= 47.4747474747474747...
x= 0.4747474747474747...
99x=
x= 47
99
. .
so 100x = 47.47
. .
Multiply!
Subtract!
Divide!
The algebra of
recurring decimals
47
Steps:
1. Write the recurring decimal out to nine decimal places
2. Multiply the decimal by powers of 10 until the part of the
decimal that repeats is in full at the front
3. Write the amount that you multiplied by ‘𝑥’ = the result from
above
4. Write ‘𝑥 = ′ the original decimal
5. Subtract the two
6. Divide to get 𝑥 =
The algebra of
recurring decimals
Recurring
Decimals
Change 0.39 into a fraction
. .
Let x= 0.39
100x= 39.3939393939393939...
x= 0.3939393939393939...
99x=
x= 39
99
. .
so 100x = 39.39
. .
Multiply!
Subtract!
Divide!
39
Recurring
Decimals
Change 0.39 into a fraction
. .
Let x= 0.39
100x= 39.3939393939393939...
x= 0.3939393939393939...
99x=
x= 39
99
. .
so 100x = 39.39
. .
Multiply!
Subtract!
Divide!
39
=13 as required
33
Recurring
Decimals
Challenge
0.45
.
Challenge
0.45
.
Let x= 0.45
.
Challenge
0.45
.
Let x= 0.45
.
so 100x = 45.5
.
100x= 45.555555555555555…
x= 0.455555555555555…
Challenge
0.45
.
Let x= 0.45
.
so 100x = 45.5
.
100x= 45.555555555555555…
x= 0.455555555555555…
Challenge
0.45
.
Let x= 0.45
.
so 100x = 45.5
.
100x= 45.555555555555555…
x= 0.455555555555555…
Challenge
0.45
.
Let x= 0.45
.
so 100x = 45.5
.
100x= 45.555555555555555…
x= 0.455555555555555…
Challenge
0.45
.
Let x= 0.45
.
99x= 45.1
so 100x = 45.5
.
100x= 45.555555555555555…
x= 0.455555555555555…
Challenge
0.45
.
Let x= 0.45
.
99x= 45.1
990x= 451
so 100x = 45.5
.
100x= 45.555555555555555…
x= 0.455555555555555…
Challenge
0.45
.
Let x= 0.45
.
99x= 45.1
990x= 451
x= 451
990
=41
90
so 100x = 45.5
.
Change 0.213 into a fraction
. .
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
. .
so 1000x = 213.213
. .
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
. .
so 1000x = 213.213
. .
Multiply!
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
1000x= 213.213213213213213...
x= 0.213213213213213...
. .
so 1000x = 213.213
. .
Multiply!
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
1000x= 213.213213213213213...
x= 0.213213213213213...
. .
so 1000x = 213.213
. .
Multiply!
Subtract!
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
1000x= 213.213213213213213...
x= 0.213213213213213...
. .
so 1000x = 213.213
. .
Multiply!
Subtract!
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
1000x= 213.213213213213213...
x= 0.213213213213213...
999x=
. .
so 1000x = 213.213
. .
Multiply!
Subtract!
213
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
1000x= 213.213213213213213...
x= 0.213213213213213...
999x=
. .
so 1000x = 213.213
. .
Multiply!
Subtract!
Divide!
213
Recurring
Decimals
Change 0.213 into a fraction
. .
Let x= 0.213
1000x= 213.213213213213213...
x= 0.213213213213213...
999x=
x= 213
999
. .
so 1000x = 213.213
. .
Multiply!
Subtract!
Divide!
213
Recurring
Decimals
Change these recurring decimals into fractions.
Recurring
Decimals
1. 0. 45
2. 0. 235
3. 0.28
4. 0.213 (This is different from the previous example.)
(= 0.235235235….)
Change these recurring decimals into fractions.
Recurring
Decimals
1. 0. 45
2. 0. 235
3. 0.28
4. 0.213
=
45
99
Change these recurring decimals into fractions.
Recurring
Decimals
1. 0. 45
2. 0. 235
3. 0.28
4. 0.213
=
45
99
=
235
999
Change these recurring decimals into fractions.
Recurring
Decimals
1. 0. 45
2. 0. 235
3. 0.28
4. 0.213
=
45
99
=
235
999
=
26
90
Change these recurring decimals into fractions.
Recurring
Decimals
1. 0. 45
2. 0. 235
3. 0.28
4. 0.213
=
45
99
=
235
999
=
26
90
=
211
990
To convert
fractions to
decimals and
vice versa
To convert a
recurring
decimal to a
fraction
To convert
fractions to
decimals and
vice versa
To convert a
recurring
decimal to a
fraction
Extension
Convert the recurring decimal 2.136 to a mixed number.
Give your answer in its simplest form.
Extension
Convert the recurring decimal 2.136 to a mixed number.
Give your answer in its simplest form.
x=2.136 1000x=2136.363636…
1000x=2136.36363636…
10x= 21.36363636…
990x= 2115
x=
2115
990
= 2
115
990
= 2
23
198
Extension
Convert the recurring decimal 2.06 to a mixed number.
Give your answer in its simplest form.
Extension
Convert the recurring decimal 2.06 to a mixed number.
Give your answer in its simplest form.
x=2. 06 100x=206.66666666…
100x=206.66666666…
10x= 20.66666666…
90x=186
x=
186
90
= 2
6
90
= 2
1
15
How do we convert
recurring decimals to
fractions?

Recurring decimals