West Kent Learning Federation

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West Kent Learning Federation
Mathematics Course
Defensive Exam Techniques
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1. Work out 45 of 24
Incorrect notation for money gets penalised
Similarly 10.80p is wrong and worth
just 1 mark
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17.99101 or
18 1 mark
18.0 2 marks
The zero is necessary to show the 3rd sig. fig.
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3. 11cm
10cm
15cm
Calculate the area of the trapezium
A large number of candidates did not use the
given formula Candidates need to be reminded
that they are expected to supply units in area
and volume questions if units are not given in
the answer space (Examiners Report)
and then cm² gets a mark even if the numerical
answer is wrong!
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4. This stem and leaf diagram shows the marks,
out of 50, of 15 candidates
in a test. 0 4 9 1 0 2 3 4 7 2 1 2 4 9 3 1
3 4 4 8 2 1 means 21
a) i) The range
The range was often left in the form 4 - 48
rather than subtracting to give 44
(Examiners Report)
4 to 48, 4 - 48, 48 - 4 0 marks
44 1 mark
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4. This stem and leaf diagram shows the marks,
out of 50, of 15 candidates
in a test. 0 4 9 1 0 2 3 4 7 2 1 2 4 9 3 1
3 4 4 8 2 1 means 21
a) ii) The median
Many found the median using the leaf values
only
(Examiners Report)
1 0 marks
21 1 mark
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4. This stem and leaf diagram shows the marks,
out of 50, of 15 candidates
in a test. 0 4 9 1 0 2 3 4 7 2 1 2 4 9 3 1
3 4 4 8 2 1 means 21
b) One of these candidates is picked at
random. What is the probability that this
candidates score is less than 22 marks?
Probabilities should be given as fractions,
decimals or percentages
8 out of 15, 815 etc 1 mark
or 0.53.. or 53... 2 marks
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5. Use your calculator to work out the value
of
Give your answer to 1 decimal place.
Notice 3 marks available - show intermediate
answers in full and hopefully earn at least one
mark
correct answer of 41.2
for 3 marks but most
incorrect answers 0 marks unless
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6. Jim and Marie drove up to the filling
station. Jim bought 47.4 litres of diesel. It
cost 35.98 Marie bought 29.7 litres of
diesel. How much did it cost?
The majority of candidates scored at least one
mark. Premature rounding caused the accuracy
mark to be lost
answers between 22.54 and 22.57 2 marks
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7. The equation of a straight line is
y4x-3 a) Write down i) the coordinates
of the point where the line crosses the y-axis
ii) the gradient of the line.
Many drew a graph in order to find the
intercept and gradient Notice there is only
one mark for each part and the instruction to
write down suggests you should be able to
answer the question without working
anything out.
i) (0,-3) 1 mark (-3,0) or -3 0
marks ii) 4 1 mark
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7. b) Rearrange y4x-3 to make x the
subject.
Notice there are two marks available. This
suggests that probably two steps will be needed,
so you can pick up one mark for doing just the
first correctly.
so y 34x also gets 1 mark
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8. Write 80 as the product of prime
numbers.
Some candidates failed to express their prime
factors as a product
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9.
a) points plotted to within 1mm
1 mark
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Lines of best fit do not normally go
through the origin

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b) line of best fit between 25 and 40 at 20
and
between 65 and 75 at 70 1 mark
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c) 41 to 46 dependent on your drawn line
1 mark
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10. The table gives information about the
times 60 teachers take to travel to
school. Time in minutes Frequency Angle Less
than 10 5 Between 10
and 15 15 Between 15 and 20 12
More than 20 28
30? 90? 72? 168?
all angles drawn within 2? 3 marks or two angles
drawn or all angles calculated 2 marks or
one angle drawn or calculated 1 mark
labelled sectors 1 mark
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21 6 and 21 1 mark each
Graph questions take time and therefore tend to
be worth quite a few marks. Sometimes these can
be easy to obtain and you should not throw them
away. This question, admittedly, is on the harder
side, but there are still some straightforward
marks to be scored.
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6 of YOUR points (out of 7) plotted correctly
gets 1 mark so if you couldnt do part a), make
two answers up and plot them!
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Curves need to be smooth, not a series
of straight lines
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No tram-lines and no thick pencils
either!
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Try to memorise that y x2 type graphs are
always smooth ? or ? shapes. If your plot is
strange, one of your points is wrong!
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Your curve doesnt have to be brilliant - just a
reasonable attempt, with a sharp pencil, at a
curve going within 1 or 2 mm of the plotted
points
Good curve 1 mark
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c) Use your graph to solve
2x2x5 Notice two marks, so expect to give two
answers (one mark each)
Note the follow through marks available
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DO NOT OBLITERATE YOUR WORKING!
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There are still too many candidates disinclined
to display any working out which means that
the available method marks cannot be earned
when the final answer is incorrect
Candidates who work solely in pencil run the
risk of their work being illegible, which
frequently it is. It is these candidates, far
more than those who work in ink, who also rub
out their working, perhaps denying themselves
method marks if their answer is incorrect
The same can be said about cases like the sample
answer where working is so heavily crossed out
that it can no longer be read.
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Working should be legible, set out clearly, and
with the question to which it relates. It is
of growing concern that candidates are showing
general working elsewhere on the paper such as on
the blank pages or on the formula sheet (or
on tracing paper which will never even be seen
by the examiner). Do not hide your work at
all. If the examiner misses it, which is quite
easy to do, youve lost all those marks!
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• Defensive Examination Techniques
• Notation

• Units

• Accuracy

• Formulas

• Scale

• Graphs

• Show all Method/Working

• Use the Marks Available as a Guide