Computers

Big O notation

Big O notation is a core A-level Computers topic. Use this page to revise the main ideas, practise the common question styles, and build confidence with trace tables, pseudocode, theory recall, and scenario questions.

What Big O notation means in A-level Computers and where it appears in exam questions.

The key vocabulary, notation, and command words students must recognise for Big O notation.

Common steps used to solve or explain Big O notation questions accurately.

Typical mistakes students make in Big O notation, and how to avoid losing method marks.

How to connect Big O notation with wider A-level Computers topics for longer answers.

A quick revision plan for practising Big O notation before timed past-paper questions.

Big O notation | A-level Computers Revision Notes & Prep