Hex digits: 0-9 then A=10, B=11, C=12, D=13, E=14, F=15. (Jun 2022 Q3(a)(i): 0011 1001. Jun 2023 Q5(d)(ii): 5B.)
Conversion
Method
Binary → Denary
Denary → Binary
Binary → Hex
Hex → Binary
Arithmetic and shifts — fill in the table
Term
Definition
Binary addition
Overflow
Two's complement
Logical shift left
Logical shift right
Arithmetic shift right
Why hexadecimal is used in computing — fill in the table
Point
Detail
Shorthand for binary
Fewer errors
Easy conversion
Used in
Jun 2023 Specimen Q1(f)(ii): "hexadecimal is used as shorthand for binary — uses fewer digits — so humans make fewer mistakes". Do NOT say hex saves memory/storage — it doesn't; it's for human readability only.
Exam questions — 4 questions · 10 marks · from real 1CP2 past papers
1 markWhy hex is used1CP2 Specimen Q1(f)(ii) style
Why is hexadecimal used by programmers rather than binary?
A Hexadecimal uses less storage space than binary
B Hexadecimal is shorthand for binary — using fewer digits makes it easier for humans to read and reduces errors
C Hexadecimal is processed faster by the CPU
D Hexadecimal can represent more values than binary
2 marksBinary to hex conversion1CP2 Jun 2022 Q3(a)(i)-(ii) style
Convert the denary number 57 to binary. Then convert your binary answer to hexadecimal. Show your working. (2 marks)
Hint: Convert denary → binary using place values (128,64,32,16,8,4,2,1). Then split into two nibbles and convert each to one hex digit.
+20 XP
2 marksTwo's complement1CP2 Jun 2022 Q3(a)(iii) style
Describe how to find the two's complement of a binary number. (2 marks)
Hint: Two steps: (1) flip all bits → (2) add 1. Both steps needed for the mark.
+20 XP
1 markOverflow1CP2 Jun 2022 Q3(a)(iv) style
When adding two 8-bit binary numbers, what is an overflow error?
A When the result is negative
B When the result is too large to be stored in the available number of bits, causing an incorrect result