This document provides three options for converting fractions to decimals. It begins by explaining the "unitary method" where knowing the decimal equivalent of one fraction (e.g. 1/5 = 0.2) allows calculating other fractions with the same denominator. It then shows long division and repeated division by 2 as two other options. Examples are provided to illustrate each method, with the goal being to memorize some common fraction-decimal conversions to easily calculate other values. Additional online resources are included for more practice.

1. Conversions: fractions to decimals
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2. How to change a fraction to a
decimal
Make sure you know the most commonly
used fractions as decimals.
If you know what 1/5 is as a decimal, you
can work out 3/5 by multiplying by 3.
e.g. 1/5 = 0.2
Therefore 3/5 = 3 x 0.2 = 0.6

3. So the first step could be to make sure you know:
½ = 0.5
¼ = 0.25 therefore ¾ = 0.75
From ¼ (0.25) you can easily work out 1/8 = 0.125
(In other words 0.25 is divided by 2 because 1/8 is half of ¼)
Useful to know - Part 1:
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4. Make sure you know these fractions as decimals too:
1/5 = 0.2
1/6 = 0.166
1/8 = 0.125
1/3 = 0.333
You will then be able to calculate other decimals through
multiplication e.g. 2/3 = 0.666666….
Useful to know - Part 2:
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5. 1/5 = 0.2 therefore 4/5 = 0.8
1/3 = 0.333 therefore 2/3 = 0.666 (given to 3 decimal
places)
From 1/3 you can work out 1/6 = 0.166
In other words 0.333 is divided by 2 because 1/6 is half of
1/3
Knowing a few fractions to decimals by heart, you will then
be able to calculate others.
Useful to know - Part 3:
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6. ½ = 0.5
¼ = 0.25 ¾ =
1/3 = 0.333 2/3 =
1/5 = 0.2 2/5 = 3/5 =
1/6 = 0.166 5/6 =
1/8 = 0.125 3/8 = 5/8 =
Knowing the first column, work out
the other columns
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Answers on next slide

7. ½ = 0.5
¼ = 0.25 ¾ = 0.75
1/3 = 0.333 2/3 = 0.666
1/5 = 0.2 2/5 = 0.4 3/5 = 0.6
1/6 = 0.166… 5/6 = 0.83
1/8 = 0.125 3/8 = 0.375 5/8 = 0.625
Learn the first column.Work out
the other columns
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8. Fractions to decimals – Option 1
Option 1:
Use the ‘unitary’ method i.e. remembering 1/5 is 0.2 allows
us to say
2/5 = 2 x 0.2 = 0.4

9. Fractions to decimals – Option 1
Option 1: using the ‘unitary’ method i.e. remembering 1/8 =
0.125 allows us to say
7/8 = 7 x 0.125 = 0.875

10. Option 2:
Another way to convert 7/8 is to complete the following
operation:
7 divided by 8 = 0.875 by what some may remember as ‘long
division’.
See this worked out on the next slide.
Fractions to decimals – Option 2
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11. Option 2: 7 divided by 8 = 0.875 by what some may
remember as ‘long division’ – see below:
Fractions to decimals – Option 2
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12. Option 3:
We have just found the answer to 7/8 as a decimal i.e. that
7 divided by 8 = 0.875
Most of us find it much easier to divide by smaller numbers
so we could divide
7 by 2 = 3.5 then
3.5 divided by 2 = 1.75 and finally
1.75 divided by 2 = 0.875
This works because 2 x 2 x 2 = 8
See this worked out again on the next slide.
Fractions to decimals – Option 3
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13. Option 3: 7 divided by 8 = 0.875 by dividing by 2, then
dividing by 2 again and finally diving by 2 yet again.This
works because 2x2x2=8.
Conversions: fractions to decimals
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14. http://www.bbc.co.uk/bitesize/ks2/maths/number/fractions_t
o_decimals/play/
http://www.mathsisfun.com/converting-fractions-
decimals.html
http://www.webmath.com/fract2dec.html
http://www.cimt.plymouth.ac.uk/projects/mepres/book7/bk7i
17/bk7_17i2.htm
http://www.mathplayground.com/fractions_convert.html
Need more practice:
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15. You can suggest additional resources by adding a
comment below our numeracy blog post.
Good luck!
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