AQA AS Level Computer Science
7517 ENTIRE SPECIFICATION
What is data abstraction? -Answer--A methodology that hides how a compound data
object is constructed, isolating how it is used from its implementation.
What is problem abstraction/reduction? -Answer--Removing details from a problem
until it is represented in a way that can be solved.
What is decomposition? -Answer--Breaking a problem into sub-problems so that
each accomplishes an identifiable task.
What is composition (abstraction)? -Answer--Building compound procedures by
combining existing procedures or building compound data objects by combining
existing data objects.
What is automation? -Answer--Putting abstract models into action to solve problems
by creating algorithms and executing code.
What is a Finite State Machine (FSM) without output? -Answer--A model of
computation represented by a state transition diagram or table, showing how the
machine moves between states based on input.
What is the set of natural numbers N? -Answer--N = {0, 1, 2, 3, ...} — used for
counting.
What is the set of integers Z? -Answer--Z = {..., -3, -2, -1, 0, 1, 2, 3, ...} — all whole
numbers, positive, negative, and zero.
What is a rational number? -Answer--A number that can be written as a fraction
(ratio of two integers).
What is an irrational number? -Answer--A number that cannot be written as a
fraction, e.g. sqrt(2) or pi.
What is the set of real numbers R? -Answer--The set of all possible real-world
quantities — includes natural, rational, and irrational numbers.
, What are ordinal numbers? -Answer--Numbers that describe the position of objects
in an ordered sequence (1st, 2nd, 3rd, etc.).
What are natural numbers used for, and what are real numbers used for?
-Answer--Natural numbers are used for counting; real numbers are used for
measurement.
What are the three number bases you must know? -Answer--Decimal (base 10),
Binary (base 2), Hexadecimal (base 16).
Why is hexadecimal used as shorthand for binary? -Answer--Each hex digit
represents exactly 4 bits, making binary values compact and human-readable.
How is a number's base expressed in notation? -Answer--Using a subscript — e.g.
67(base 10), 10011011(base 2), AE(base 16).
What is a bit? -Answer--The fundamental unit of information — it is either 0 or 1.
What is a byte? -Answer--A group of 8 bits.
How many different values can n bits represent? -Answer--2^n different values.
What is 1 KiB (kibibyte)? -Answer--2^10 bytes = 1,024 bytes.
What is 1 MiB (mebibyte)? -Answer--2^20 bytes.
What is 1 GiB (gibibyte)? -Answer--2^30 bytes.
What is 1 TiB (tebibyte)? -Answer--2^40 bytes.
What is 1 kB (kilobyte)? -Answer--10^3 = 1,000 bytes.
What is 1 MB (megabyte)? -Answer--10^6 bytes.
What is 1 GB (gigabyte)? -Answer--10^9 bytes.
What is 1 TB (terabyte)? -Answer--10^12 bytes.
What is unsigned binary? -Answer--A binary representation of non-negative integers
only.
What is signed binary (two's complement)? -Answer--A binary representation of both
negative and positive integers.
7517 ENTIRE SPECIFICATION
What is data abstraction? -Answer--A methodology that hides how a compound data
object is constructed, isolating how it is used from its implementation.
What is problem abstraction/reduction? -Answer--Removing details from a problem
until it is represented in a way that can be solved.
What is decomposition? -Answer--Breaking a problem into sub-problems so that
each accomplishes an identifiable task.
What is composition (abstraction)? -Answer--Building compound procedures by
combining existing procedures or building compound data objects by combining
existing data objects.
What is automation? -Answer--Putting abstract models into action to solve problems
by creating algorithms and executing code.
What is a Finite State Machine (FSM) without output? -Answer--A model of
computation represented by a state transition diagram or table, showing how the
machine moves between states based on input.
What is the set of natural numbers N? -Answer--N = {0, 1, 2, 3, ...} — used for
counting.
What is the set of integers Z? -Answer--Z = {..., -3, -2, -1, 0, 1, 2, 3, ...} — all whole
numbers, positive, negative, and zero.
What is a rational number? -Answer--A number that can be written as a fraction
(ratio of two integers).
What is an irrational number? -Answer--A number that cannot be written as a
fraction, e.g. sqrt(2) or pi.
What is the set of real numbers R? -Answer--The set of all possible real-world
quantities — includes natural, rational, and irrational numbers.
, What are ordinal numbers? -Answer--Numbers that describe the position of objects
in an ordered sequence (1st, 2nd, 3rd, etc.).
What are natural numbers used for, and what are real numbers used for?
-Answer--Natural numbers are used for counting; real numbers are used for
measurement.
What are the three number bases you must know? -Answer--Decimal (base 10),
Binary (base 2), Hexadecimal (base 16).
Why is hexadecimal used as shorthand for binary? -Answer--Each hex digit
represents exactly 4 bits, making binary values compact and human-readable.
How is a number's base expressed in notation? -Answer--Using a subscript — e.g.
67(base 10), 10011011(base 2), AE(base 16).
What is a bit? -Answer--The fundamental unit of information — it is either 0 or 1.
What is a byte? -Answer--A group of 8 bits.
How many different values can n bits represent? -Answer--2^n different values.
What is 1 KiB (kibibyte)? -Answer--2^10 bytes = 1,024 bytes.
What is 1 MiB (mebibyte)? -Answer--2^20 bytes.
What is 1 GiB (gibibyte)? -Answer--2^30 bytes.
What is 1 TiB (tebibyte)? -Answer--2^40 bytes.
What is 1 kB (kilobyte)? -Answer--10^3 = 1,000 bytes.
What is 1 MB (megabyte)? -Answer--10^6 bytes.
What is 1 GB (gigabyte)? -Answer--10^9 bytes.
What is 1 TB (terabyte)? -Answer--10^12 bytes.
What is unsigned binary? -Answer--A binary representation of non-negative integers
only.
What is signed binary (two's complement)? -Answer--A binary representation of both
negative and positive integers.
