2210 · 0478Paper 2 · Algorithms, Programming and Logic

7. Algorithm Design and Problem-Solving

Program development life cycle, decomposition, flowcharts and pseudocode, standard algorithms (searching, sorting, totalling, counting, max/min), validation and testing with trace tables.

Read the Smart Notes Watch lectures (13)

Statometer87BankerNext Paper 294%

Marks a paper20.6 · 28%Rank#4 of 10 · #2 on P2Trend · last 12↘Full stats

Everything for this topic — study hub

O Level / IGCSE · 2210 · 0478 · Paper 2

Statometer — what 25 real papers say about this topic and each of its 6 syllabus bullets

Banker · #4 of 10 in O Level / IGCSE · recomputed with every new session

Banker#4 of 10 in O Level / IGCSE#2 on Paper 2↘ Easing

Set in nearly every paper and worth a big slice of it — revise first, expect it.

Next Paper 2: 94%; 9 in 10 chance it is set
Marks a paper: 20.6 / 75; 28% of Paper 2 · fair share 25%
Appeared in: 25 / 25; Paper 2 sittings 2023–2026
Last set: May/Jun 2026; 0478/23 · Q5 · 7 marks · 11-series streak

Marks in each of the last 12 Paper 2 sittingsOct/Nov 24 → May/Jun 26

What the papers say

Set in 25 of 25 Paper 2 sittings on the current syllabus — treat it as certain.
Worth about 20.6 marks a paper (28% of Paper 2).
Last set May/Jun 2026 · 0478/23 · Q5 for 7 marks — in the most recent series.
Set in each of the last 11 series without a miss.
Easing off: about 25.2 marks a paper earlier, 18.1 in the latest years — still examined, just smaller.
Lives on “Complete” and “Describe” — 45% of its questions: you must produce something — code, a diagram, a table — practise doing it, not reading it.
54% of its questions involve a diagram, table or figure — practise with pen and paper.
57% of its questions are set out as code, pseudocode or a table to complete.
Most of its marks (80%) come in extended questions of 6+ marks — plan the answer before writing.
Its biggest question so far: 16 marks (Oct/Nov 2023 · 0478/21 · Q8).
Inside the topic, Test data (normal, abnormal, extreme, boundary); trace tables for dry runs; identifying and correcting errors in algorithms carries the most marks (24%) and The program development life cycle the least (3%).
It is examined mostly as AO2 (Apply to a context, 66%), the rest AO1 (28%) — you must apply it to the scenario or the given data — a definition alone will not score.
The examiner has commented on 159 of its questions — read “What the examiner said” before you practise.

Command words

Share of questions using the word (a question can use several). What each wants →

Question shapes

1–2 mk25
3–4 mk59
5–6 mk84
7–9 mk86
10+ mk42

Average 6.8 marks a question · 54% with a figure or table · 57% with code · biggest 16 marks

Assessment objectives — how it is examined

Every part of every current-syllabus question filed under Cambridge's AO1 / AO2 / AO3 (from its command word and what it asks you to do), so you know whether this topic pays for definitions, for applying, or for judging and building.

AO1 28%

AO2 66%

AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge

Paper 2 as a whole

Paper 2	Syllabus	Measured
AO1 Knowledge & understanding	20%	27%
AO2 Apply to a context	60%	51%
AO3 Evaluate & judge	20%	22%

Syllabus = Cambridge's grid; measured = the bank's current-syllabus papers.

Inside the topic — every syllabus bullet, measured

Each part of each question is filed under the bullet it examines; the numbers are per Paper 2 sitting, exactly like the topic's. Open a bullet for its own Statometer.

The program development life cycle#15 of 19 on Paper 2Occasional · 3346% next paper1.7 marks12/25 sittings→ May/Jun 2026Occasional · 3346%
1.7 · 3% of topic12/25May/Jun 2026latest series · →
Rotated in occasionally — the bullet students skip and then meet.Syllabus: analysis, design, coding and testing, and what happens at each stage
Next Paper 2
46%
2 in 4
Marks a paper
1.7
2% of the paper · 3% of the topic
Asked in
12 / 25
Paper 2 sittings · 19 questions
Last asked
May/Jun 2026
2210/22 · Q4 · 3 marks
Asked in 12 of 25 Paper 2 sittings — roughly one paper in 2.
About 1.7 marks a paper (2% of Paper 2; 3% of the topic's marks across its 6 bullets).
Last asked May/Jun 2026 · 2210/22 · Q4 (3 marks) — in the most recent series.
Usually “Identify”: short, precise answers in syllabus words.
Biggest chunk of marks so far: 6 in Feb/Mar 2026 · 0478/22 · Q3.
It is examined almost entirely as AO1 (Knowledge & understanding, 98%) — definitions and descriptions in syllabus words score.
Last 12 sittings→ Steady
Assessment objectives
AO1 98%
AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge
Identify32%
Describe26%
Tick21%
State16%
Practise its 19 questions Biggest: 6 marks · Feb/Mar 2026
Sub-systems and decomposition (inputs, processes, outputs, storage); designing solutions with structure diagrams, flowcharts and pseudocode#9 of 19 on Paper 2Core · 5879% next paper3.1 marks20/25 sittings↘ May/Jun 2026Core · 5879%
3.1 · 17% of topic20/25May/Jun 2026latest series · ↘
A regular earner inside the topic — most papers touch it.
Next Paper 2
79%
8 in 10
Marks a paper
3.1
4% of the paper · 17% of the topic
Asked in
20 / 25
Paper 2 sittings · 97 questions
Last asked
May/Jun 2026
0478/23 · Q5 · 2 marks · 4-series streak
Asked in 20 of 25 Paper 2 sittings — about 8 papers in 10.
About 3.1 marks a paper (4% of Paper 2; 17% of the topic's marks across its 6 bullets).
Last asked May/Jun 2026 · 0478/23 · Q5 (2 marks) — in the most recent series.
Asked in each of the last 4 series.
Easing: 3.7 → 2.5 marks a paper.
Usually “Complete”: you must produce something — code, a diagram, a table — practise doing it, not reading it.
Biggest chunk of marks so far: 8 in May/Jun 2025 · 0478/23 · Q1.
It is examined mostly as AO2 (Apply to a context, 66%), the rest AO1 (34%) — you must apply it to the scenario or the given data — a definition alone will not score.
Last 12 sittings↘ Easing
Assessment objectives
AO1 34%
AO2 66%
AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge
Complete55%
Write17%
Describe16%
Explain14%
Practise its 97 questions Biggest: 8 marks · May/Jun 2025
Explaining the purpose of a given algorithm; standard methods of solution#11 of 19 on Paper 2Regular · 5471% next paper2.9 marks18/25 sittings↘ May/Jun 2026Regular · 5471%
2.9 · 19% of topic18/25May/Jun 2026latest series · ↘
Set most sessions for a few marks; know the definition and one example.Syllabus: linear search, bubble sort, totalling, counting, maximum/minimum/average
Next Paper 2
71%
7 in 10
Marks a paper
2.9
4% of the paper · 19% of the topic
Asked in
18 / 25
Paper 2 sittings · 78 questions
Last asked
May/Jun 2026
0478/23 · Q3 · 0.5 marks · 11-series streak
Asked in 18 of 25 Paper 2 sittings — about 7 papers in 10.
About 2.9 marks a paper (4% of Paper 2; 19% of the topic's marks across its 6 bullets).
Last asked May/Jun 2026 · 0478/23 · Q3 (0.5 marks) — in the most recent series.
Asked in each of the last 11 series.
Easing: 4.6 → 2 marks a paper.
Usually “Complete”: you must produce something — code, a diagram, a table — practise doing it, not reading it.
Biggest chunk of marks so far: 8 in May/Jun 2023 · 0478/23 · Q7.
It is examined almost entirely as AO2 (Apply to a context, 82%) — you must apply it to the scenario or the given data — a definition alone will not score.
Last 12 sittings↘ Easing
Assessment objectives
AO1 18%
AO2 82%
AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge
Complete50%
Explain28%
Describe24%
Identify21%
Practise its 78 questions Biggest: 8 marks · May/Jun 2023
Validation checks (range, length, type, presence, format, check digit) and verification checks (visual, double entry)#7 of 19 on Paper 2Core · 6275% next paper3.7 marks20/25 sittings→ May/Jun 2026Core · 6275%
3.7 · 19% of topic20/25May/Jun 2026latest series · →
A regular earner inside the topic — most papers touch it.
Next Paper 2
75%
7 in 10
Marks a paper
3.7
5% of the paper · 19% of the topic
Asked in
20 / 25
Paper 2 sittings · 84 questions
Last asked
May/Jun 2026
0478/23 · Q3 · 10 marks · 10-series streak
Asked in 20 of 25 Paper 2 sittings — about 8 papers in 10.
About 3.7 marks a paper (5% of Paper 2; 19% of the topic's marks across its 6 bullets).
Last asked May/Jun 2026 · 0478/23 · Q3 (10 marks) — in the most recent series.
Asked in each of the last 10 series.
Usually “Give” or “Describe”: short, precise answers in syllabus words.
Biggest chunk of marks so far: 10 in May/Jun 2026 · 0478/23 · Q3.
It is examined mostly as AO1 (Knowledge & understanding, 54%), the rest AO2 (37%) — definitions and descriptions in syllabus words score.
Last 12 sittings→ Steady
Assessment objectives
AO1 54%
AO2 37%
AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge
Give33%
Describe31%
Explain30%
Identify23%
Practise its 84 questions Biggest: 10 marks · May/Jun 2026
Test data (normal, abnormal, extreme, boundary); trace tables for dry runs; identifying and correcting errors in algorithms#4 of 19 on Paper 2Banker · 8287% next paper5.4 marks23/25 sittings→ May/Jun 2026Banker · 8287%
5.4 · 24% of topic23/25May/Jun 2026latest series · →
Asked in nearly every paper — the bullet to know cold.
Next Paper 2
87%
9 in 10
Marks a paper
5.4
7% of the paper · 24% of the topic
Asked in
23 / 25
Paper 2 sittings · 98 questions
Last asked
May/Jun 2026
0478/23 · Q5 · 5 marks · 11-series streak
Asked in 23 of 25 Paper 2 sittings — nearly every paper.
About 5.4 marks a paper (7% of Paper 2; 24% of the topic's marks across its 6 bullets).
Last asked May/Jun 2026 · 0478/23 · Q5 (5 marks) — in the most recent series.
Asked in each of the last 11 series.
Usually “Complete”: you must produce something — code, a diagram, a table — practise doing it, not reading it.
Biggest chunk of marks so far: 9 in Oct/Nov 2024 · 2210/23 · Q7.
It is examined almost entirely as AO2 (Apply to a context, 78%) — you must apply it to the scenario or the given data — a definition alone will not score.
Last 12 sittings→ Steady
Assessment objectives
AO2 78%
AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge
Complete50%
Describe30%
Give28%
State24%
Practise its 98 questions Biggest: 9 marks · Oct/Nov 2024
Writing and amending algorithms for a scenario in pseudocode, program code and flowcharts#12 of 19 on Paper 2Regular · 4555% next paper2.7 marks15/25 sittings↘ May/Jun 2026Regular · 4555%
2.7 · 18% of topic15/25May/Jun 2026latest series · ↘
Set most sessions for a few marks; know the definition and one example.
Next Paper 2
55%
6 in 10
Marks a paper
2.7
4% of the paper · 18% of the topic
Asked in
15 / 25
Paper 2 sittings · 78 questions
Last asked
May/Jun 2026
2210/21 · Q10 · 6 marks · 11-series streak
Asked in 15 of 25 Paper 2 sittings — about 6 papers in 10.
About 2.7 marks a paper (4% of Paper 2; 18% of the topic's marks across its 6 bullets).
Last asked May/Jun 2026 · 2210/21 · Q10 (6 marks) — in the most recent series.
Asked in each of the last 11 series.
Easing: 3.1 → 2.5 marks a paper.
Usually “Write”: you must produce something — code, a diagram, a table — practise doing it, not reading it.
Biggest chunk of marks so far: 6 in May/Jun 2026 · 2210/21 · Q10.
It is examined almost entirely as AO2 (Apply to a context, 100%) — you must apply it to the scenario or the given data — a definition alone will not score.
Last 12 sittings↘ Easing
Assessment objectives
AO2 100%
AO1 Knowledge & understanding
AO2 Apply to a context
AO3 Evaluate & judge
Write62%
Describe22%
Give17%
Complete17%
Practise its 78 questions Biggest: 6 marks · May/Jun 2026

12% of the topic's marks sit in question parts that belong to another topic (scenario questions cross sections) or that no bullet claims; they count for the topic, not for a bullet.

Marks a paper, year by year

1011121314151617181920212223242526

Grey years are the previous syllabus (2010–2022, 205 questions) — history, not counted in the rates.

By exam series

Feb/Mar4/4 · 26.8 mk
May/Jun12/12 · 21.4 mk
Oct/Nov9/9 · 20.6 mk

Practise 296 real questions Smart Notes Quiz Flashcards Every topic on the Statometer

What you need to know6syllabus section 7

The program development life cycle — analysis, design, coding and testing, and what happens at each stage
Sub-systems and decomposition (inputs, processes, outputs, storage); designing solutions with structure diagrams, flowcharts and pseudocode
Explaining the purpose of a given algorithm; standard methods of solution — linear search, bubble sort, totalling, counting, maximum/minimum/average
Validation checks (range, length, type, presence, format, check digit) and verification checks (visual, double entry)
Test data (normal, abnormal, extreme, boundary); trace tables for dry runs; identifying and correcting errors in algorithms
Writing and amending algorithms for a scenario in pseudocode, program code and flowcharts

Video lectures13ZAK's YouTube channel · play here

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Infographics3draw these the way the examiner expects · download as PNG

Flowchart symbols & the PDLC

O LevelAS

Bubble sort & linear search

O LevelAS

Choosing test data

O LevelAS

Browse all infographics →

Key terms11use these exact words in the exam

abstraction decompositionflowchartpseudocodelinear searchbubble sortvalidation verification trace tabletest databoundary data

Dotted terms are defined in the glossary.

Code help4referenced to the Cambridge pseudocode guide

Linear search

pseudocode 9618 §7.3 WHILE Run in Playground

DECLARE A : ARRAY[1:6] OF INTEGER
DECLARE i, Target : INTEGER
DECLARE Found : BOOLEAN
A[1] ← 8
A[2] ← 3
A[3] ← 9
A[4] ← 1
A[5] ← 7
A[6] ← 4
Target ← 7
Found ← FALSE
i ← 1
WHILE i <= 6 AND NOT Found DO
   IF A[i] = Target THEN
      Found ← TRUE
   ELSE
      i ← i + 1
   ENDIF
ENDWHILE
IF Found THEN
   OUTPUT "Found at position ", i
ELSE
   OUTPUT "Not found"
ENDIF

Bubble sort with a swapped flag

pseudocode Run in Playground

DECLARE A : ARRAY[1:5] OF INTEGER
DECLARE i, Temp : INTEGER
DECLARE Swapped : BOOLEAN
A[1] ← 5
A[2] ← 1
A[3] ← 4
A[4] ← 2
A[5] ← 3
REPEAT
   Swapped ← FALSE
   FOR i ← 1 TO 4
      IF A[i] > A[i + 1] THEN
         Temp ← A[i]
         A[i] ← A[i + 1]
         A[i + 1] ← Temp
         Swapped ← TRUE
      ENDIF
   NEXT i
UNTIL NOT Swapped
FOR i ← 1 TO 5
   OUTPUT A[i]
NEXT i

💡 Open the Trace Table tab after running — this is the classic Paper 2 trace question.

Totalling, counting, max, min, average

pseudocode Run in Playground

DECLARE Marks : ARRAY[1:5] OF INTEGER
DECLARE i, Total, Count, Max, Min : INTEGER
Marks[1] ← 67
Marks[2] ← 91
Marks[3] ← 45
Marks[4] ← 78
Marks[5] ← 84
Total ← 0
Count ← 0
Max ← Marks[1]
Min ← Marks[1]
FOR i ← 1 TO 5
   Total ← Total + Marks[i]
   IF Marks[i] >= 50 THEN
      Count ← Count + 1
   ENDIF
   IF Marks[i] > Max THEN
      Max ← Marks[i]
   ENDIF
   IF Marks[i] < Min THEN
      Min ← Marks[i]
   ENDIF
NEXT i
OUTPUT "Total ", Total, " Passes ", Count, " Max ", Max, " Min ", Min, " Avg ", Total / 5

Validation: range + presence with re-prompt

pseudocode Run in Playground

DECLARE Age : INTEGER
REPEAT
   OUTPUT "Enter age 5-120"
   INPUT Age
   IF Age < 5 OR Age > 120 THEN
      OUTPUT "Out of range, try again"
   ENDIF
UNTIL Age >= 5 AND Age <= 120
OUTPUT "Accepted ", Age

Playground examples24runnable programs for this topic

Swap two variables
The three-line swap with a temporary variable — a favourite trace-table question.
O LevelASPseudocodeBasics & data types §1.5
Run
FOR loop & totalling
A count-controlled loop that accumulates a running total.
O LevelASPseudocodeIteration §7.1
Run
WHILE with a sentinel — totalling & counting
Read numbers until -1; INPUT once before the loop and again at the end of the body.
O LevelASPseudocodeIteration §7.3 · 2210 WHILE … DO
Run
Maximum, minimum & average
The standard algorithm: start Highest very low and Lowest very high, then update as you go.
O LevelASPseudocodeIteration 2210 §7.1 standard methods
Run
Counting — how many passed?
Two counters updated inside a loop, then a percentage.
O LevelASPseudocodeIteration 2210 §7.1 standard methods
Run
Total, average and position of the maximum
Keep the index of the best value, not just the value, so you can say where it was.
O LevelASPseudocodeArrays §3.2
Run
Range check
Keep asking until the value is between 0 and 100.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Presence & length checks
Nothing entered? Too short or too long? Say which check failed.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Type check — digits only
A function that tests every character before the string is converted to a number.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Format check — is this an email address?
One @ that is not first, and a dot after it that is not last.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Check digit — ISBN-13
Weights 1 and 3 alternate, total MOD 10, subtract from 10. The classic check-digit algorithm.
O LevelASPseudocodeValidation, testing & exceptions 2210 §2.3, §7.3
Run
Verification — double entry
Validation checks the data is sensible; verification checks it was entered correctly.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Trace table practice
A typical dry-run question. Run it, then open the Trace table tab and check it against your own table.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.4 / 9618 §12.3
Run
Normal, boundary and abnormal test data
Drive a function with each kind of test data and check the results against what you expected.
ASPseudocodeValidation, testing & exceptions 9618 §12.3
Run
Linear search
Check each element in turn and stop as soon as the target is found.
O LevelASPseudocodeSearching 2210 §7.1 / 9618 §9.2
Run
Linear search — every match
Do not stop at the first hit: report every position and count them.
O LevelASPseudocodeSearching 2210 §7.1
Run
Bubble sort
Compare neighbours and swap; after each pass the largest value has bubbled to the end.
O LevelASPseudocodeSorting 2210 §7.1 / 9618 §9.2
Run
Sort names alphabetically
Bubble sort works on strings too: "Ali" < "Zara" compares character codes.
O LevelASPseudocodeSorting 2210 §7.1
Run
O Level Section B — a week of temperatures
Validate seven readings into an array, then report the average and the hottest day. Everything Paper 2 Section B expects in one program.
O LevelPseudocodeExam-style tasks 2210 §7–8
Run
O Level Section B — cinema booking
Ticket types with CASE, quantities, a running total and a group discount.
O LevelPseudocodeExam-style tasks 2210 §7–8
Run
Totalling, counting, max, min, average
The standard loop pattern with a list — and then the built-ins sum(), max(), min(), len() that do it in one line.
O LevelASPythonIteration §7.1 ↔ Python
Run
Validation loop — range and type checks
Keep asking until the input is a whole number between 1 and 100. try/except catches the ValueError from int().
O LevelASPythonValidation, testing & exceptions §7.3 ↔ Python, A2 §20.3
Run
Linear search
Walk the list until you find the target — the exam wants the loop, not list.index().
O LevelASPythonSearching §7 ↔ Python
Run
Bubble sort with a swapped flag
The classic Paper 2 / Paper 4 sort. Open the Trace tab to watch the swaps.
O LevelASPythonSorting §7 ↔ Python
Run

Flowchart Studio12draw-it-yourself tasks and worked flowcharts, run and checked box by box

Area of a rectangle
Input two numbers, multiply, output — the simplest complete flowchart.
O LevelASSequence & I/O 2210 §7
Open
Celsius to Fahrenheit
A formula in a process box; the exam's favourite two-line calculation.
O LevelSequence & I/O 2210 §7
Open
Pass or fail
One decision, two output boxes, arrows that rejoin before Stop.
O LevelSelection 2210 §7
Open
Largest of three numbers
Nested decisions: the chart shows why the second comparison depends on the first.
O LevelASSelection 2210 §7
Open
Total and average of N numbers
Totalling and counting together, then a division after the loop — the classic 2210 Q.
O LevelASTotalling, counting, max / min 2210 §7
Open
Total until −1 (rogue value)
A sentinel-controlled loop: read, test, add, read again.
O LevelASTotalling, counting, max / min 2210 §7
Open
Highest and lowest of 10 marks
Set max low and min high, then one decision each inside the loop.
O LevelASTotalling, counting, max / min 2210 §7
Open
Count how many passed
A counter that only increments inside a decision.
O LevelTotalling, counting, max / min 2210 §7
Open
Range check with a rejection loop
Keep asking until the value is between 1 and 100 — the validation flowchart every paper wants.
O LevelASValidation & rejection loops 2210 §7
Open
Presence check
A WHILE loop that rejects an empty string.
O LevelValidation & rejection loops 2210 §7
Open
Linear search
Search an array for a value with a found flag — 2210 §7's standard method.
O LevelASArrays 2210 §7
Open
One pass of a bubble sort
Compare neighbours and swap: the decision inside the loop with three process boxes.
O LevelASArrays 2210 §7
Open

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Quiz: Algorithm Design & Problem-Solving (45)🃏 Flashcards: mix this topic (66)🧭 PDLC, decomposition & design tools (21)🔍 Standard algorithms (15)🧪 Validation, verification & test data (17)📋 Trace tables & finding errors (13)Past-paper questions (296)🏆 Programming tasks (auto-marked)🔀 Flowchart Studio 📊 Sorting & searching visualiser 📋 Trace tables 🧪 Test data, validation & check digits

Everything for this topic — study hub

Statometer — what 25 real papers say about this topic and each of its 6 syllabus bullets

What you need to know6syllabus section 7

Video lectures13ZAK's YouTube channel · play here

Prog. Basics 2 · Good Programming Practices · Validation Veri · Lib. Routines · O/AS Level

Verification & Validation · O & AS Levels

Making of & Fill · Flowcharts · URDU · OL Class

Tracing Pseudocode · Removing Errors · OL

Flowcharts · Tracing · Validations Checks · Verification · Top Down Design · OL & IGCSE

Finding Errors in Given Pseudocodes · More PP Questions · Library Routines · OL & IGCSE

Infographics3draw these the way the examiner expects · download as PNG

Key terms11use these exact words in the exam

Code help4referenced to the Cambridge pseudocode guide

Playground examples24runnable programs for this topic

Flowchart Studio12draw-it-yourself tasks and worked flowcharts, run and checked box by box

Ready to check you know it?