IGCSE COMPUTER SCIENCE - 1.1 DATA
REPRESENTATION EXAM QUESTIONS
AND ANSWERS
Machine code
1st Generation language - Answer-The 1s and 0s that make up the instructions for a
computer. This is the lowest level of programming language that all programs must be
converted to in order to be executed on a computer. Computers only understand
machine code.
Assembly language
2nd generation language - Answer-One step up from machine code where the individual
machine code instructions are represented as simple keywords such as ADD or BRA.
Requires an assembler to turn it into machine code.
High level language
3rd generation language. - Answer-A computer programming language that is much
closer to a human language than machine code. Examples of high level languages are
Python, PHP, Visual Basic and C (although there are lots more!). Requires and
interpreter or a compiler to turn it into machine code.
Bit - Answer-A single binary digit. A bit will be either a 1 or a 0.
Nibble - Answer-4 bits is equivalent to a single hexadecimal digit.
e.g. 0111 = 7, 1010 = A, 1111 = F
Byte - Answer-8 bits. Can be used to represent any denary number from 0 to 255 (that's
256 different combinations!).
Kilobyte - Answer-1024 or 2^10 bytes.
Megabyte (Mb) - Answer-1024 kilobytes.
Gigabyte (Gb) - Answer-1024 megabytes.
Terabyte (Tb) - Answer-1024 gigabytes.
Binary - Answer-The number system we use to represent the data stored in a digital
computer. Binary is a base 2 number system and uses the digits 1 and 0.
Hexadecimal - Answer-A base 16 number system that we use to represent the data
stored in a digital computer. Hexadecimal is used instead of binary for two reasons: 1. It
REPRESENTATION EXAM QUESTIONS
AND ANSWERS
Machine code
1st Generation language - Answer-The 1s and 0s that make up the instructions for a
computer. This is the lowest level of programming language that all programs must be
converted to in order to be executed on a computer. Computers only understand
machine code.
Assembly language
2nd generation language - Answer-One step up from machine code where the individual
machine code instructions are represented as simple keywords such as ADD or BRA.
Requires an assembler to turn it into machine code.
High level language
3rd generation language. - Answer-A computer programming language that is much
closer to a human language than machine code. Examples of high level languages are
Python, PHP, Visual Basic and C (although there are lots more!). Requires and
interpreter or a compiler to turn it into machine code.
Bit - Answer-A single binary digit. A bit will be either a 1 or a 0.
Nibble - Answer-4 bits is equivalent to a single hexadecimal digit.
e.g. 0111 = 7, 1010 = A, 1111 = F
Byte - Answer-8 bits. Can be used to represent any denary number from 0 to 255 (that's
256 different combinations!).
Kilobyte - Answer-1024 or 2^10 bytes.
Megabyte (Mb) - Answer-1024 kilobytes.
Gigabyte (Gb) - Answer-1024 megabytes.
Terabyte (Tb) - Answer-1024 gigabytes.
Binary - Answer-The number system we use to represent the data stored in a digital
computer. Binary is a base 2 number system and uses the digits 1 and 0.
Hexadecimal - Answer-A base 16 number system that we use to represent the data
stored in a digital computer. Hexadecimal is used instead of binary for two reasons: 1. It
