2025 AQA AS COMPUTER SCIENCE 7516/2
Paper 2
Question paper and Marking scheme Merged
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
COMPUTER SCIENCE
Paper 2
Monday 19 May 2025 Afternoon Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a calculator.
Question Mark
Instructions 1
• Use black ink or black ball-point pen. 2
• Fill in the boxes at the top of this page.
3
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write outside 4
the box around each page or on blank pages. 5
• If you need extra space for your answer(s), use the lined pages at the end of 6
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want to 7
be marked. 8
9
Information
• The marks for questions are shown in brackets. 10
• The maximum mark for this paper is 75. 11
12
Advice
• In some questions you are required to indicate your answer by completely 13
shading a lozenge alongside the appropriate answer as shown.
TOTAL
• If you want to change your answer you must cross out your original answer as
shown.
• If you wish to return to an answer previously crossed out, ring the answer you
now wish to select as shown.
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Which two of the numbers below belong to the set of numbers represented by ℤ?
Shade two lozenges.
[2 marks]
A 0
B √2
C π
3
D
4
E 998
0 1 . 2 Describe what is meant by the term ‘ordinal number’.
[1 mark]
0 1 . 3 Explain why real numbers are better suited to representing measurements of some
quantities than natural numbers.
[1 mark]
4
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IB/G/Jun25/7516/2
, 3
Do not write
outside the
0 2 . 1 How many different values can be represented using one byte? box
[1 mark]
0 2 . 2 The bit pattern in Figure 1 represents an 8-bit unsigned binary integer.
Figure 1
0 1 0 0 0 0 1 1
Convert the bit pattern in Figure 1 to decimal.
[1 mark]
0 2 . 3 Show how the 8-bit unsigned binary number 01001111 can be added to the 8-bit
unsigned binary number 00001011 without converting the numbers into decimal.
You must show all your working in binary.
[2 marks]
0 1 0 0 1 1 1 1
+ 0 0 0 0 1 0 1 1
Turn over ►
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IB/G/Jun25/7516/2
, 4
Do not write
outside the
0 2 . 4 What are the lowest and highest values that can be represented by a box
4-bit two’s complement binary integer?
Give your answers in decimal.
[2 marks]
Lowest
Highest
0 2 . 5 Using 8-bit two’s complement binary, what is the result of subtracting 00110100
from 01101101?
Give your answer in 8-bit two’s complement binary.
You must show all your working in binary.
[3 marks]
0 2 . 6 Represent 5.75 as an 8-bit unsigned fixed point binary number with four bits before
and four bits after the binary point.
[2 marks]
11
for more: tyrionpapers.com
IB/G/Jun25/7516/2
Paper 2
Question paper and Marking scheme Merged
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
COMPUTER SCIENCE
Paper 2
Monday 19 May 2025 Afternoon Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a calculator.
Question Mark
Instructions 1
• Use black ink or black ball-point pen. 2
• Fill in the boxes at the top of this page.
3
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write outside 4
the box around each page or on blank pages. 5
• If you need extra space for your answer(s), use the lined pages at the end of 6
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want to 7
be marked. 8
9
Information
• The marks for questions are shown in brackets. 10
• The maximum mark for this paper is 75. 11
12
Advice
• In some questions you are required to indicate your answer by completely 13
shading a lozenge alongside the appropriate answer as shown.
TOTAL
• If you want to change your answer you must cross out your original answer as
shown.
• If you wish to return to an answer previously crossed out, ring the answer you
now wish to select as shown.
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Which two of the numbers below belong to the set of numbers represented by ℤ?
Shade two lozenges.
[2 marks]
A 0
B √2
C π
3
D
4
E 998
0 1 . 2 Describe what is meant by the term ‘ordinal number’.
[1 mark]
0 1 . 3 Explain why real numbers are better suited to representing measurements of some
quantities than natural numbers.
[1 mark]
4
for more: tyrionpapers.com
IB/G/Jun25/7516/2
, 3
Do not write
outside the
0 2 . 1 How many different values can be represented using one byte? box
[1 mark]
0 2 . 2 The bit pattern in Figure 1 represents an 8-bit unsigned binary integer.
Figure 1
0 1 0 0 0 0 1 1
Convert the bit pattern in Figure 1 to decimal.
[1 mark]
0 2 . 3 Show how the 8-bit unsigned binary number 01001111 can be added to the 8-bit
unsigned binary number 00001011 without converting the numbers into decimal.
You must show all your working in binary.
[2 marks]
0 1 0 0 1 1 1 1
+ 0 0 0 0 1 0 1 1
Turn over ►
for more: tyrionpapers.com
IB/G/Jun25/7516/2
, 4
Do not write
outside the
0 2 . 4 What are the lowest and highest values that can be represented by a box
4-bit two’s complement binary integer?
Give your answers in decimal.
[2 marks]
Lowest
Highest
0 2 . 5 Using 8-bit two’s complement binary, what is the result of subtracting 00110100
from 01101101?
Give your answer in 8-bit two’s complement binary.
You must show all your working in binary.
[3 marks]
0 2 . 6 Represent 5.75 as an 8-bit unsigned fixed point binary number with four bits before
and four bits after the binary point.
[2 marks]
11
for more: tyrionpapers.com
IB/G/Jun25/7516/2
