Recursion & Base Cases in Python|Cambridge A - Level 9618|PPT|Worksheet|Activity|MCQ|Mark Scheme

Make recursion click with a complete lesson that’s ready to go.

Recursion is one of the topics students find hardest, because they have to follow code that calls itself. This pack builds the idea step by step, from a simple countdown to tracing the call stack, so students can write, trace and explain recursive functions with confidence. It is aligned to Cambridge A-Level Computer Science 9618 and needs no prep.

WHAT’S INCLUDED

• PowerPoint lesson ([X] slides): animated call-stack diagrams, worked examples and built-in check-for-understanding questions

• Student worksheet ([X] pages): scaffolded tasks from recall, to tracing recursive calls, to exam-style problems

• Hands-on coding activity: students write recursive functions such as factorial, sum of a list, power and string reversal

• MCQ quiz ([X] questions): quick-fire questions to check understanding and catch misconceptions

• Answers and full mark scheme: model answers with mark allocations, so marking takes minutes

WHAT STUDENTS WILL LEARN

What recursion is, and how it differs from iteration
The base case (stopping condition) and the recursive case
How the call stack works: stack frames building up (winding) and returning (unwinding)
Tracing recursive functions step by step to predict the output
Classic examples: factorial, Fibonacci, sum of a list, power, and reversing a string
Why the order of output changes depending on where the print statement sits
Recursion vs iteration: advantages and disadvantages, including memory use and readability
Converting a recursive solution to an iterative one, and the reverse
Stack overflow and Python’s recursion limit
Recursive functions in Cambridge pseudocode
Common errors: a missing or unreachable base case, forgetting to return the recursive call, and mixing up the order of winding and unwinding

WHY TEACHERS LOVE IT

Exam-focused: questions follow Cambridge command words and mark-scheme style
Targets real misconceptions: the mistakes students make every year, especially tracing the unwinding stage
Differentiated: support tasks plus stretch questions for top-grade students
Non-specialist friendly: clear explanations and full answers included
Flexible: works as a single lesson, homework, cover or revision
Print-and-go: no editing needed (editable PPT included)

PERFECT FOR
Cambridge A-Level 9618 teachers, heads of department, non-specialist and cover staff, and students learning independently. It suits ages 16-18 (Year 12-13 / Grade 11-12).

PART OF A FULL SERIES
This pack belongs to my Cambridge 9618 Python and Algorithms collection. Check my shop for matching packs on algorithms, data structures, OOP and the complete Python course.

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