# GCSE Computer Science Revision

These links to free revision resources are designed to allow you to quickly recap and/or check your understanding of various topics - they are not aimed at in-depth revision. Most of our students take OCR Computer Science, but all GCSEs have similar content.

## General

- Connecting Wall - identify and group the related Computer Science terms
- Computing Worderama - identify key Computer Science terms from the GCSE specification

## Number Bases

- Binary - check your conversion skills
- Binary Breakout - binary/denary conversion game
- Binary Counter - see how the digits change (also useful for completing truth tables)
- Hexadecimal - check your understanding (only two digits required for GCSE)
- Binary and Hexadecimal - converting directly between the two

## Representation and File Sizes

- Calculating File Sizes - YouTube playlist
- Metadata - why do we need it?
- Representing images - what do the numbers mean?
- Representing sound - record a sound, see the waveform and samples, and calculate for the file size
- Sampling - see the impact of sampling rate and sample size on recorded sound
- Character sets - see the range of Unicode characters
- Compression - see Run-Length Encoding and Huffman Coding in action

## Algorithms - Sorting and Searching

- Bubble Sort Game - check your understanding of the steps required
- Merge Sort Game - check your understanding of the steps required
- Insertion Sort Game - check your understanding of the steps required
- Sorting algorithms - see how many steps are required for different sorting algorithms
- Binary search - practise performing a binary search
- Bubble Sort Python program - explains the steps as required for a GCSE answer
- Merge Sort Python program - explains the steps as required for a GCSE answer
- Insertion Sort Python program - explains the steps as required for a GCSE answer
- Binary Search program - explains the steps as required for a GCSE answer

## Programming

- The Silent Teacher - programming logic test
- Programming Concepts Crossword - familiarise yourself with programming terms from the specification
- Spot the Error - recognise common mistakes
- Algorithm-a-Day - practice algorithm questions for paper 2
- Strings in ERL - ERL string manipulation methods reproduced in Python (in case they come up on paper 2)
- GCSE Python Guide - using OCR terminology and showing where ERL differs from Python

## Boolean Logic

- Boolean Logic - a reminder of what the common logical operators do
- Logic Circuits - how the logic gates are used in circuits
- Name the Logic Gate - practice with truth tables and recognising logic functions

## Other

- SQL Injection - activity with link to video explanation
- Hardware/Processor Crossword - familiarise yourself with terms related to hardware and the fetch-execute cycle
- Computer Science Dingbats - revise key vocabulary
- Impact of Computing - news articles and examples that you can include in longer answers
- Long Answers - some generic points that you can use with most contexts

## Proper Revision

All of the links above are to quick tests or reminders to fill a few spare minutes - the links below are for more exam-focussed revision.

- Clickschool for OCR J277 (they also have AQA notes) - includes questions at the ends of sections and downloadable flashcards
- Seneca Revision - also available for other subjects
- Six-a-Day - past paper questions in bite-size chunks