Computer Science: Revising Programming and Theory
Head Mark Coaching12 October 2026 1 min read
How to prepare for the theory and the programming parts of Computer Science, and how to practise code on paper.
Computer Science has two kinds of questions: theory, which you learn and explain, and programming or logic, which you practise. Prepare for both.
Theory
- Make short notes with headings for every chapter and learn definitions word for word.
- Draw diagrams for things such as the parts of a computer, networks and number systems.
- Use comparison tables, for example hardware and software, or RAM and ROM.
- Test yourself by covering the answer and explaining the term in your own words.
Number systems and logic
Binary, decimal and hexadecimal conversions are easy marks if you practise. Do five conversions a day and show the steps. Learn the truth tables for AND, OR and NOT and draw a few logic circuits by hand.
Programming
- Understand the problem and write the steps in plain words first (an algorithm).
- Draw a small flowchart if it is complicated.
- Then write the code.
- Trace it with sample values on paper, line by line, to check it works.
Common mistakes
- Missing brackets, semicolons or indentation.
- Using a variable before giving it a value.
- Off-by-one errors in loops.
- Not stating the output clearly in trace questions.
Practise daily
Even twenty minutes of coding or tracing each day builds confidence. Revise past papers to see which question types are repeated.