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Converting Fractions – Decimals - Percentages
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Percentages are amounts out of 100
Fraction
Decimal
Percentage
1
/2
24
/60
4 1/8
0.16
0.006
2.8
65%
140%
0.0.00025
Use
0.025%
Calculator Key
Divide by 100 or
Multiply by 100
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Converting Fractions – Decimals - Percentages
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Enter fraction or
decimal into calculator
Fraction
Decimal
Calculator
100
%
100
ab/c
100
100
Percentage
Gamma
p29 Ex 3.01
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Fractions of & Percentages of something
Which is the best deal?
20% of $34 or
15% of $42
SKILLS
 Find % of a value.
eg 26% of 250 =
Calculator use!
 Write as a percentage
eg I get 14 out of 40 in a test. What is my % mark?
eg 8 of a class of 28 are late. What % are on time?
eg A watch looses 8 seconds a day. What % is this?
 Find original value
eg 12% of x is $42 so x =
eg 45% of x is $125 so x =
.
.
Fractions of & Percentages of something
Which is the best deal?
20% of $34 or
15% of $42
SKILLS
 Find % of a value.
eg 34% of $250 =
 Find Fraction of a value.
eg 2/7 of $250 =
Calculator use!
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Fractions of & Percentages of Examples
Question
Working
$520 x
.
Answer
28
/100
28% of $520
$
(or) $520 x 0.28
4% of $84
$84 x 4/100
$
(or) $84 x 0.04
$62 x
130% of $62
130
/100
$
(or) $62 x 1.3
Calculator Use:
'Shift =' makes the
% function:
62 x 130 %
62 x 130 'shift ='
(amount first, % second)
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Finding the Original Amount
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Gamma
p30 Ex 3.02
Find original value
eg 12% of ? is $42 so ? =
eg 45% of ?? is $125 so ?? =
Finding 28% of
something
Multiply by 0.28 to
get the new amount
DIVIDE by 0.28 to
get the ORIGINAL
amount
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Finding the Original Amount Examples
.
Question
Working
28% of Farmer Bobs sheep are
going to be sold. 154 sheep were
sold. How many sheep were there
altogether?
Original x 0.28 = 154
So…
65% of apples produced by Farmer Original x 0.65 = 364
Bob are exported. There were 364 So…
cartons exported.
How many cartons were NOT
exported?
Answer