percentages % % % % chris clements understanding percentage as the number of parts in every 100
TRANSCRIPT
Percentages
% %
%% Chris Clements
Understanding percentage as the number of parts in every
100
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Learning Objective:
LO: I know that 'per cent' means parts in every 100 .
The word ‘percentage’ originates from a Latin word meaning by the hundred.
Percentage (%)
Can you think of any words that begin with ‘cent’?
centipede
century
cents
What do you notice?
Look at the square. 100% of is shaded purple. Can you see it is made up of 100 equal parts?
What percentage of the shape is shaded purple now?What percentage of the shape is shaded white?
90% 10% 100%+ =
What percentage of the shape is shaded white?
What percentage of the shape is shaded purple?
50% 50% 100%+ =What fraction is equivalent to 50%?
What percentage of the shape is shaded white?
What percentage of the shape is shaded purple?
25% 75% 100%+ =What fraction is equivalent to 25%?What fraction is equivalent to 75%?
Now the square is made up of 10 different colours.
What percentage of each colour is there?
10% 10 100%x =
What fraction is 10% equivalent to?
What percentage of the shape is shaded white?
What percentage of the shape is shaded purple?
37% 63% 100%+ =
What percentage of the shape is shaded white?What percentage of the shape is shaded purple?
61% 39% 100%+ =
What percentage of the shape is shaded white?What percentage of the shape is shaded purple?
88% 12% 100%+ =
What percentage of the shape is shaded white?What percentage of the shape is shaded red?
30% 50% 100%+ =
What percentage of the shape is shaded purple?
20%+
What percentage of the shape is shaded white?What percentage of the shape is shaded red?
35% 35% 100%+ =
What percentage of the shape is shaded purple?
30%+
What percentage of the shape is shaded white?What percentage of the shape is shaded red?
22% 56% 100%+ =
What percentage of the shape is shaded purple?
22%+
What percentage of the shape is shaded white?What percentage of the shape is shaded red?
50% 46% 100%+ =
What percentage of the shape is shaded purple?
4%+
What do you notice about this shape?
To work out the percentage we first need to find what % each part is worth?
To do this we need to divide a 100 by the number of parts.
100%
÷ 20 = 5% Each part = 5%
What percentage of the shape is shaded purple?5% x 13 = 65%
What percentage of the shape is shaded white?
65%
+ 35% = 100%
5% x 7 = 35%
100 ÷ 2 (no. of parts) = 50%Each part of this shape = 50%
So 50% is shaded blue 50% is shaded white
Steps to success1) Remember one whole is equal to
100%2) Find the percentage of parts
shaded3) Check to see if the unshaded part
+ the shaded part = 100For shapes not divided into 100 parts. Use this formula to work out what percentage each part is worth;
100 ÷ No. of parts in a shape = % of each part
Plenary
Can you match the percentages to
the same value fraction?
50%25%
75%10%
½ ¼
¾
110
34% 58%
91%46% 23%
Which of these fractions show more than ½?
19%