Download 5649_34 Practice Paper 2F - Set C mark scheme

Specification B – Practice Paper C
Mark Scheme
GCSE
GCSE Mathematics (Modular)
Paper: 5MB2F_01
GCSE MATHEMATICS
UNIT 2 PRACTICE PAPER C MARKSCHEME
NOTES ON MARKING PRINCIPLES
1
Types of mark
M marks: method marks
A marks: accuracy marks
B marks: unconditional accuracy marks (independent of M marks)
2
Abbreviations
cao – correct answer only
isw – ignore subsequent working
oe – or equivalent (and appropriate)
indep - independent
ft – follow through
SC: special case
dep – dependent
3
No working
If no working is shown then correct answers normally score full marks
If no working is shown then incorrect (even though nearly correct) answers score no marks.
4
With working
If there is a wrong answer indicated on the answer line always check the working in the body of the script (and on any
diagrams), and award any marks appropriate from the mark scheme.
If working is crossed out and still legible, then it should be given any appropriate marks, as long as it has not been
replaced by alternative work.
If it is clear from the working that the “correct” answer has been obtained from incorrect working, award 0 marks. Send
the response to review, and discuss each of these situations with your Team Leader.
If there is no answer on the answer line then check the working for an obvious answer.
Any case of suspected misread loses A (and B) marks on that part, but can gain the M marks. Discuss each of these
situations with your Team Leader.
If there is a choice of methods shown, then no marks should be awarded, unless the answer on the answer line makes
clear the method that has been used.
Paper: 5MB2F_01
Session: Practice Paper C
2
GCSE MATHEMATICS
UNIT 2 PRACTICE PAPER C MARKSCHEME
5
Follow through marks
Follow through marks which involve a single stage calculation can be awarded without working since you can check the
answer yourself, but if ambiguous do not award.
Follow through marks which involve more than one stage of calculation can only be awarded on sight of the relevant
working, even if it appears obvious that there is only one way you could get the answer given.
6
Ignoring subsequent work
It is appropriate to ignore subsequent work when the additional work does not change the answer in a way that is
inappropriate for the question: e.g. incorrect canceling of a fraction that would otherwise be correct
It is not appropriate to ignore subsequent work when the additional work essentially makes the answer incorrect e.g.
algebra.
Transcription errors occur when candidates present a correct answer in working, and write it incorrectly on the answer
line; mark the correct answer.
7
Probability
Probability answers must be given a fractions, percentages or decimals. If a candidate gives a decimal equivalent to a
probability, this should be written to at least 2 decimal places (unless tenths).
Incorrect notation should lose the accuracy marks, but be awarded any implied method marks.
If a probability answer is given on the answer line using both incorrect and correct notation, award the marks.
If a probability fraction is given then cancelled incorrectly, ignore the incorrectly cancelled answer.
8
Linear equations
Full marks can be gained if the solution alone is given on the answer line, or otherwise unambiguously indicated in
working (without contradiction elsewhere). Where the correct solution only is shown substituted, but not identified as
the solution, the accuracy mark is lost but any method marks can be awarded.
9
Parts of questions
Unless allowed by the mark scheme, the marks allocated to one part of the question CANNOT be awarded in another.
10
Use of ranges for answers
If an answer is within a range this is inclusive, unless otherwise stated.
Paper: 5MB2F_01
Session: Practice Paper C
3
GCSE MATHEMATICS
UNIT 2 PRACTICE PAPER C MARKSCHEME
Question
(a)
1
2
Working
Answer
Mark
(6, 7)
1
B1 cao
(b)
(3, 6)
1
B1 cao
(c)(i)
Plotting point
1
B1 for plotting point correctly
(c)(ii)
Plotting point
1
B1 for plotting point correctly
(a)
1466
1
B1 cao
(b)
561
1
3.85
2
(a)
4s
1
B1 cao
M1 for 7.35 – 3.50
A1 cao
B1 oe
(b)
4ab
1
B1 oe
(a)
Parallel lines marked
1
B1 cao
(b)
Right angle marked
1
B1 cao
(c)(i)
Acute
1
B1 ignore spelling
(c)(ii)
reflex
1
B1 ignore spelling
(a)
23
1
B1 cao
(b)
47
1
95
2
90p or £0.90
3
B1 cao
M1 for squaring 4 or multiplying out bracket
A1 cao
M1 for attempt to divide 18 by 20
A1 for 90 or 0.9
C1 for writing sum of money correctly
7.35 – 3.50
3
4
5
(c)
6
7
Paper: 5MB2F_01
Session: Practice Paper C
5(3 + 16)
£18 ÷ 20
1800 ÷ 20 = 90
2.50
10.00
3.00
5.00
24.00
£3
£2.50
£24
£42
4
Notes
B1
B1
B1
B1
for £3
for £2.50
for £24
ft for £42
4
GCSE MATHEMATICS
UNIT 2 PRACTICE PAPER C MARKSCHEME
Question
(a)
8
9
Working
Answer
82
Mark
1
(b)
70
1
(c)
explanation
1
(d)
102 – 4n
2
(a)
1 more square
1
(b)
1 more square
1
(c)
Correct shape
1
(d)
Correct shape
1
10
23 –14 + 3
12
2
11
(56 ÷ 8) × (30 ÷ 6) × (36 ÷ 12)
Or
(56 × 30 × 12) ÷ (8 × 6 × 12)
105
3
12
Angle ABE = 65º (opposite angles of
a parallelogram are equal)
Angle x = 180 – 65 = 125 (angles in a
straight line add to 180º)
125
4
Paper: 5MB2F_01
Session: Practice Paper C
Notes
B1 cao
B1 cao
C1 for explanation e.g. 23 is odd and all the members
of the sequence are even
M1 for linear term in – 4n (e.g. 98 – 4n)
A1 for 102 – 4n
B1 for a correct square added
B1 for a correct square added
B1 for a correct shape that has 2 lines of symmetry e.g.
rectangle
B1 for a correct shape with rotational symmetry of
order 2 but no lines of symmetry e.g. parallelogram
M1 for 23 – 14 + 3 oe
A1 for 12
M1 for attempt to find the number of boxes along one
length of a carton or attempt to find the volume of a
box or the carton
M1 for attempt to multiply their 7, 5 and 3 or divide
their volumes
A1 for 105 cao
M1 for Angle ABE = 65º
C1 for opposite angles of a parallelogram are equal
M1 for Angle x = 180 – 65 = 125
C1 for angles in a straight line add to 180º
5
GCSE MATHEMATICS
UNIT 2 PRACTICE PAPER C MARKSCHEME
Question
Working
Answer
Mark
256
54 ×
1024
12800
13824
×
200
50
6
50
10000
2500
300
4
800
200
24
M1 for complete method for multiplying 200, 50 and 6
by 4 and 50 condone one error in multiplication
M1 (dep) for addition condone one addition error
A1 cao for 13 824
10 000 + 2500 + 300 + 800 + 200 + 24
= 13 824
13
2
1
5
1
2
0
8
8
y= –1 , , 3,
14
(b)
Paper: 5MB2F_01
Session: Practice Paper C
3
0
2
0
2
, 7, 9
13 824
3
M1 for complete method for multiplying 2, 5 and 6 by 5
and 4 condone one error in multiplication
M1 (dep) for addition condone one addition error
A1 cao for 13 824
6
5
2
3
(a)
Notes
M1 for complete method for multiplying 256 by 4 and
50 condone one error in multiplication
M1 (dep) for addition condone one addition error
A1 cao for 13 824
4
5
4
4
Table of
values
Straight
line from
(−2, −1)
2
2
B2 for 4 values of y correct
(B1 for 2 or 3 values correct)
B2 for a correct straight line from (−2, −1) to (3, 9)
[B1 ft for at least 5 correctly plotted points OR a single
line passing through (0, 3) OR for a single line of
6
GCSE MATHEMATICS
UNIT 2 PRACTICE PAPER C MARKSCHEME
to (3, 9)
Question
Working
=
Mark
1800
3
(a)
x9
1
(b)
4
y
1
18
5
15
16
=
Answer
gradient 2)
2×⅜=¾
14 ÷ ¾ = 18⅔
17
Paper: 5MB2F_01
Session: Practice Paper C
Notes
M1 for correct attempt to write 2 numbers correct to 1
significant figure
M1 for correct attempt to establish 360 ÷ 0.2
A1 cao
B1 cao
B1 cao
M1 for attempt to double ⅜
A1 for ¾
M1 for attempt to find how many ¾ there are in 14 by
dividing or by counting on
A1 for 18⅔ or realizing that it will me more than 18
C1 for rounding to 18 rather than 19 or sufficient
explanation from their attempt at division
7