computational thinking

Cambrdige AS level computer science 2025. Textbook references: Cambridge International AS and A level computer science coursebook Sylvia Langfield, David Duddell 2019 press ||| Cambrdige International AS and A Levels Computer science by David Wastson, Helen Williams press 2019

what is computational thinking used for

to study a problem and formulate an effective solution

what is abstraction

extracting information and only including what is necessary to solve that problem

what is in computational thinking

abstraction, decomposition, pattern recognition

what do you need to keep in mind in abstraction

purpose and information

what is decomposition

process of breaking a complex problem into smaller parts until a smallest unit is found

what is used for decomposition

flowcharts, structure diagrams

what is pattern recognition

identification of parts of a problem and could use the same solution

what are algorithms

ordered set of steps to be followed

what is structured english

agreed subset of straightforward english words that consists of command statements used to describe an algorithm

what is a flowchart

diagrammatic representation of an algorithm

what is pseudocode

a way of using keywords and identifies to describe an algorithm without following the syntax of a particular programming language

what is stepwise refinment

subdividing each part of a larger problem into a series of smaller parts

what is a logical approach to analysing a program

computational thinking

what gived the power to deal with complexity when approaching a problem?

Abstraction

what leads us to the concept of program modules and using procedures and functions?

Decomposition

what involved analysing and organising data while setting up abstract data types to model real-world concepts?

data modelling

what is data modelling

process of abstracting real-world entities into structured representations

what is an assignment

a value associated with a given identifier that can be changed

what is a sequence

number of steps that are performed one after the other

what is selection

under certain conditions some steps are performed otherwise something else is performed

what is repetition

sequence of steps performed a number of times

what is iteration

process of repeating steps

what is looping

a code structure that enables iterations

what is the scope of iteration

a single execution of the loop body

what is the scope of looping

the entired block of code that repeats

which is syntax-dependent : iteration or looping?

looping

which can occur alone via recursion or manual repetition? : iteration or looping

iteration

what is count-controlled iteration

fixed repetitions

what is condition-controlled iteration

repeating until a conditon is met

what is the focus with looping

how the repetition is implemented

what is the focus with iteration

what is beign repeated

which is conceptually broader? : iteration or looping?

iteration

how is iteration different from looping?

it is a process of repeating steps and not the conde structure that enabes it

what is this?

structured english

what is this?

pseudocode

what is this?

flowchart

what is a variable?

a storage location for a data value that has an identifier

what is an identifier table

somethinng listing the variable identifiers required for the solution

what does an identifier provide other that the variable identifiers

explanations and data types

what is a nested IF statement

conditional statements within conditional statements

what is a rogue value

a value used to terminate a sequence of values

how does a rogue value operate

its the same data type but outside the range of normal expected values

which lood do you use when…? : it is known how many repetitions are requred

FOR loop

which lood do you use when…? : statements inside the loop might never be executed

WHILE loop

which lood do you use when…? : statements inside the loop are to be executed at least once

REPEAT loop

what is a procedure

a sequence of steps that is given an identifier and can be called to perform a sub-task

what is a function

a sequence of steps that is given an identifier and returns a signle value

which returns a value? : function or procedure

function

which is called? : function or procedure

procedure

what can you use to decompose a problem into sub-tasks

Modules

functions and procedures are examples of…?

Modules

what does a function definiton state

data type of the returned value

what is an advantage of modules

each can be reused in other solutions

what is designed to be self-contained

Modules

what does it mean when a module is self-contained

does not rely on external variables

what makes a module independent and reusable?

local variables

what is a local variable

a variable that is accssible only within the module in which it is declared

what is a global variable

a variable that is accessible from all modules

which type of variable can cause issues in a program with multiple modules but used in multiple locations?

global variables

what is an identifier?

input storage location with a specified name

what is algorithm design

developing step by step instructions to solve a problem

what is similar to a recipe

an algoritm

what makes an algorithm difficult or impossible

insrtuctions are not followed in the correct logical sequence

how do you know you have a good algorithm/code

takes up little computer memory and fast to execute

what is an assignment

pratical application for problem-solving

what does an assignment intergrate

data modelling and algorithmic problem solving

what do assignments define

clear entities and relationships

what should you do when given an assignment

break down into modular functions

what is a logical statement

declarative expression that evaluates to a Boolean value

what enables conditional execution

logical statements

is this a good example of a variable name: Num of students

No

is this a good example of a variable name: Num_of_students

yes

how do you properly declare a variable

with letters, numbers, no spaces

if you can’t use spaces when declaring a variable, what do you do?

use underscores instead

where should a letter be when declaring a variable

not as the first character

what does a loop do

help avoid writing the same lines of code over and over

what is computational thinking

problem solving process where a number of steps are taken in order to reach a solution

what process of computational thinking do things like maps, calandars use

abstraction

what is manaegd by well-defined objects and their heirachial classification?

abstraction

what computational thinking method uses many standard algorithms to solve standard problems

pattern recognition

what resembles a standard program

subroutines

what do subroutines have that make it resemble a standard program

its own variables, data types, lables, constant declarations

what is a parameter

a value that is received in a subroutine

which is considered as default passing : ByRef or ByVal

ByRef

which one passes the value of the variable : ByRef or ByVal

ByVal

what happens when you change the value of a variable in ByRef passing

revised value goes back to the main code

what happens when you change the value of a variable in ByVal

changed made will not be passed back into main code

what is an assignment statement

fundemental programming construct that stores in a variable for storage and data manipulation

what is the order of execution in assignment statements

right hand expressions are fully evaluated before assignment

what is the structure of an assignment statement

variable name, assignment operator, value

why are assignment statements important

programs can’t track state, process data or make decisions dynamically

what is a sub-system

self-contained component within a larger system that performs a specifc and well defined task

what do sub-systems align with

decomposition

what is a role in program solving does a sub-system have

improving maintainability

why do sub-systems matter

enables efficient problem solving by focusing on individual tasks

what is an advataged of using sub-systems

simplified error detection

what is the wording in structured english that can be used for : input and output

enter, read, print, write

what is the wording in structured english that can be used for : selection

if, then, choose

what is the wording in structured english that can be used for : iteration

loop, repeat

what is the wording in structured english that can be used for : process

set, calculate