# maths exam

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for example

2a=10

10/2=5

2x5=10

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## converting decimals to fractions

for example:

4.25

H   T    U  .  1/10   1/100  1/1000

4  .    2           5

4 25/100

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for example

6.7 x 31

70 x 30

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## ratio

There are 15 girls and 12 boys in a class. What is the ratio of girls to boys? Give your answer in its simplest form.

The ratio of girls to boys is 15:12

However, both sides of this ratio are divisible by 3

Dividing by 3 gives 5:4

5 and 4 have no common factors (apart from 1).

So the simplest form of the ratio is 5:4

This means there are 5 girls in the class for every 4 boys.

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## changing the subject

According to the order convention, beginning with ‘u’, you add ‘at’ to get ‘v’.

The inverse operation is then to subtract ‘at’:

·       Subtract ‘at’ from both sides:

- at = u + at - at

·     Simplify:

- at = u

·      Swap sides so the subject is on the left hand side:

u  =  v - at

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2 more than x

x+2

x added to 3

x+3

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## tip to remember

two minus signs become a plus sign

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## sequences

5,9,13,17,21,25

rule: adding 4 each time

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3 and 4

12

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60

30       2

15  2

3 5

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m

/

d   x    v

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