Different Charts for Different Data

1
Module 3 (I)
2
Decimals Part 1
0.2² 0.2 x 0.2 0.04
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Decimal Part 2
1
as a decimal 1 ? 8 0.125
8
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Significant Figures

• 4 3 . 6 8 0 2 to 3 significant figures

43.7
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Proportion Part 1

• Exchange Rate

1 1.50
2 3
(x2)
10 15
(x10)
100 150
(x100)
Etc.
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Proportion Part 2

• Speed

Mph means miles per hour
(remember per means DIVIDE)
So, 30 mph means 30 miles . . . every
hour (60 mins)
( 1 mile every 2 mins)
( 15 miles every ½ an hour)
0.4 hours 0.4 x 60 mins 24 mins
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Rounding and Estimation

• 800 people to the nearest 100

• Maximum it could have been is 849

• Minimum it could have been is 750

14 cm to the nearest cm

• Maximum it could have been is 14.5 (actually
  14.4999999999999 . . . . . )

• Minimum it could have been is 13.5

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Percentage Increase/Decrease
TIP Work out and write down the actual increase
or decrease

• Eg A car goes down in value from 12,500 to
  11,000. What is the percentage decrease ?
• If you write down 1,500 you will get 1 mark

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Dividing in a given ratio

• Share 32 in the ratio of 53

5 3 8
5 x 4 20
32 ? 8 4
3 x 4 12
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Percentage

• 10 . . . . . ? 10 (take a zero off or
  jump a decimal place)

5 ½ of 10 Etc.
1 . . . . . ? 100 (take 2 zeros off or
jump 2 decimal places)
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Rules of Indices
1210 ? 122 128
512
(54)3
1
3-2
60 1 140 1
32
65 x 68 613
45 4x4x4x4x4
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Product of Prime Factors
2
4
2
32
3
8
2
2
4
96 2x2x2x2x2x3
2
25x31
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Express as a percentage

• 80 as a percentage of 500

80 x 100 16 500
80
8
16
16



500
50
100
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Estimating Answers

• Estimate means use easy numbers

• Examples
• 71 x 19 70 x 20 1400

(x10)
296 x 8.13 300 x 8 2400 24000
0.39 0.4 0.4 4
6000
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Standard Form

• 36,400 3.64 x 104
• 0.00000826 8.26 x 10-6

(3 x 104) x (2 x 1011) 6 x 1015
(2.4 x 106) ? (2 x 108 ) 1.2 x 10-2
Use the EXP button on your calculator
3.94 E 4 3.94 x 104
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Fractions of amounts

• Find 3/8 of 32

1/8 of 32 4 (32 ? 8 4)
3/8 of 32 3 x 1/8 3 x 4 12
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Adding fractions
The numbers on the bottom must be the same ! Make
two new equivalent fractions
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Multiplying fractions
Multiply the top and multiply the bottom !
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Dividing fractions
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