Y9 Recap C Percentages

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Y9 Recap CPercentages

• 28th Jan 2004

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Matching fractions, decimals and percentages M2.1
30
¾
0.2
2
?
0.125
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(No Transcript)
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Fractions, decimals and percentages spider
diagram M2.2
240
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Which parts of the web diagram did you find the
easiest to work out?
Do you find it easier to use fractions, decimals
or percentages?
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Fractions, decimals and percentages spider
diagram M2.2
40g
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Percentage problems M2.3 1 An alloy is made
from 95 copper, 3.5 tin and 1.5 zinc.
How much tin is there in 1 kg of the
alloy? 2 The population of Greece is 10
million. 37 of the population is aged 15 to
39.How many people is this? 3 An ice-cream
label lists the contents as 17.5 fat. How much
fat is there in 750 g of ice-cream? 4 A fabric
is made from 83 viscose, 10 cotton and 7
nylon.How much viscose is needed to make 1.5
tonnes of the fabric?
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Percentage problems M2.3
1 An alloy is made from 95 copper, 3.5 tin and
1.5 zinc. How much tin is there in
1 kg of the alloy?
To find 3.5
1 of 1 kg (1000g) is 10 g
3.5 is 1 1 1 0.5 10 10 10 5
35g tin
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• Percentage problems M2.3
• 1 An alloy is made from 95 copper, 3.5 tin and
  1.5 zinc. How much tin is there in
  1 kg of the alloy?
• The population of Greece is 10 million.
• 37 of the population is aged 15 to 39.How
  many people is this?
• 3 An ice-cream label lists the contents as 17.5
  fat. How much fat is there in 750 g of
  ice-cream?
• 4 A fabric is made from 83 viscose, 10 cotton
  and 7 nylon.How much viscose is needed to make
  1.5 tonnes of the fabric?

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2 The population of Greece is 10 million. 37
of the population is aged 15 to 39. How
many people is this?
To find 37
10 of 10 million is 1 million
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Percentage problems M2.3 1 An alloy is made
from 95 copper, 3.5 tin and 1.5 zinc.
How much tin is there in 1 kg of the
alloy? 2 The population of Greece is 10
million. 37 of the population is aged 15 to
39.How many people is this? 3 An ice-cream
label lists the contents as 17.5 fat. How much
fat is there in 750 g of ice-cream? 4 A fabric
is made from 83 viscose, 10 cotton and 7
nylon.How much viscose is needed to make 1.5
tonnes of the fabric?
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3 An ice-cream label lists the contents as 17.5
fat. How much fat is there in 750 g of ice-cream?
To find 17.5 of 750g
10 is 75g
17.5 of 750g is 10 5 2.5 75 37.5
18.75 131.25g of fat
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Percentage problems M2.3 1 An alloy is made
from 95 copper, 3.5 tin and 1.5 zinc.
How much tin is there in 1 kg of the
alloy? 2 The population of Greece is 10
million. 37 of the population is aged 15 to
39.How many people is this? 3 An ice-cream
label lists the contents as 17.5 fat. How much
fat is there in 750 g of ice-cream? 4 A fabric
is made from 83 viscose, 10 cotton and 7
nylon. How much viscose is needed to make 1.5
tonnes of the fabric?
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4 A fabric is made from 83 viscose, 10 cotton
and 7 nylon.How much viscose is needed to make
1.5 tonnes of the fabric?
To find 83 of 1.5 tonne
10 is 150 kg
1 is 15 kg
83 is 80 3 1 200 kg 45 kg 1 245 kg of
viscose
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Using a calculator
A 15 increase
115
1.15
1

0.15
Increase 25 by 15
25 x 1.15 28.75
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Decrease 3km by 12.5
1 0.125 0.875
( we need to find 87.5)
Decrease 3 km by 12.5 3 x 0.875 2.625 km
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Thank you for your attention