AQA 8525 · Section 3.1 · 3.1.1b

Representing
Algorithms

Pseudocode · Flowcharts · AQA Notation · Variables & Assignment

CSZone AQA GCSE Computer Science 8525

Learning Objectives

By the end of this lesson you will be able to...

Write algorithms using AQA pseudocode notation

Interpret and draw flowcharts using correct symbols

Use variables, assignment, input/output, arithmetic and comparisons in pseudocode

Convert between pseudocode and flowchart representations

Two Representations

Pseudocode vs Flowcharts

📝 PSEUDOCODE

English-like instructions, structured like code

No strict syntax rules — but AQA uses consistent notation

Good for describing logic quickly

🔷 FLOWCHARTS

Visual diagram using standard shapes

Easier for beginners to follow flow

Arrows show direction of execution

⚡ AQA Exam:You may be asked to trace, complete, or write in either format. Learn both!

Flowchart Symbols

The Standard Shapes

Shape	Name	Purpose
Rounded rectangle (oval)	Terminal	Start / End
Rectangle	Process	Any instruction or calculation
Diamond	Decision	Yes/No question — branches the flow
Parallelogram	Input / Output	Read input or display output
Arrow	Flow line	Shows direction of execution

Remember:Diamonds always have two exits (Yes/No or True/False). All other shapes have one exit.

AQA Pseudocode

Key Notation You Must Know

x ← 5
name ← 'Ahmed'
total ← total + 1

← means "assign/store"

OUTPUT 'Hello'
OUTPUT score
name ← USERINPUT

OUTPUT prints · USERINPUT reads

IF score > 50 THEN
OUTPUT 'Pass'
ELSE
OUTPUT 'Fail'
ENDIF

FOR i ← 1 TO 10
OUTPUT i
ENDFOR

AQA Operators

Arithmetic & Comparison Operators

ARITHMETIC

+	Addition
-	Subtraction
*	Multiplication
/	Division
DIV	Integer division
MOD	Remainder

COMPARISON

=	Equal to
≠	Not equal to
<	Less than
>	Greater than
<=	Less than or equal
>=	Greater than or equal

Exam Practice

Have a go at this question

AQA-style question

Write pseudocode for an algorithm that:
• Asks the user to input two numbers
• Outputs their sum and their average

4 marks

MODEL ANSWER

num1 ← USERINPUT
num2 ← USERINPUT
OUTPUT num1 + num2
OUTPUT (num1 + num2) / 2

Key Takeaways

What to Remember

AQA uses ← for assignment and USERINPUT / OUTPUT for I/O

Flowcharts use: oval (start/end) · rectangle (process) · diamond (decision) · parallelogram (I/O)

Use DIV for integer division and MOD for the remainder

Both pseudocode and flowcharts must show the same logical steps — they're two ways of saying the same thing