GCSE-readyPearson Edexcel International GCSE Computer Science (4CP0)
68 free lessons that follow the International GCSE specification topic by topic. Each lesson has short notes, a worked example and a quick check with instant marking.
International GCSE · Pearson Edexcel 4CP0
Getting started
4 lessons · about 53 minutes
Topic 1: Problem solving
9 lessons · about 2 h 30 min
- Algorithms and flowcharts 16 min
- Pearson pseudocode: variables, selection and loops 18 min
- Pearson pseudocode: arrays, subprograms and files 18 min
- Trace tables and types of error 16 min
- Searching and sorting 18 min
- Bubble sort and merge sort step by step 18 min
- Linear and binary search in code 18 min
- Evaluating algorithms and test data 15 min
- Decomposition and abstraction 13 min
Topic 2: Programming
14 lessons · about 3 h 45 min
- Python basics: data types, input and output 16 min
- Writing readable code and from algorithms to programs 14 min
- Selection: if, elif and else 15 min
- Variables, constants and operators 15 min
- Repetition and iteration: for and while 16 min
- Manipulating strings 15 min
- Formatting output and string methods 16 min
- Arrays, 2D arrays and records 16 min
- Processing 2D lists and records with loops 18 min
- Reading and writing CSV text files 16 min
- Validation and authentication 16 min
- Subprograms: functions and procedures 17 min
- Finding and fixing errors in Python 18 min
- Testing programs: test plans and test data 16 min
Topic 3: Data
13 lessons · about 3 h 20 min
- Binary numbers 17 min
- Sign and magnitude 13 min
- Two's complement signed integers 16 min
- Binary addition, overflow and shifts 17 min
- Hexadecimal 15 min
- Representing characters: ASCII 13 min
- Images, sound and the limits of bits 16 min
- Data units, images and sound 18 min
- File size and capacity calculations 18 min
- Data compression 13 min
- Run-length encoding 13 min
- Protecting systems and data 14 min
- Encryption and classic ciphers 17 min
Topic 4: Computers
13 lessons · about 3 h 10 min
- Computational models and simulation 14 min
- Hardware components and how they work together 14 min
- The CPU and the fetch-decode-execute cycle 16 min
- Buses and the stored program concept 15 min
- CPU performance and cache 14 min
- Memory and storage 14 min
- How secondary storage works 15 min
- Cloud storage and its security 13 min
- Embedded systems 12 min
- Logic gates and truth tables 16 min
- Truth tables with three inputs 15 min
- Operating systems and utility software 15 min
- Programming languages and translators 15 min
Topic 5: Communication and the internet
9 lessons · about 2 h 15 min
- Networks, LANs, WANs and the internet 15 min
- PANs, network models, ring topology and mobile networks 15 min
- Wired, wireless and network speed 16 min
- Network and email protocols 14 min
- The TCP/IP model 14 min
- Network topologies 14 min
- Network security and robust software 15 min
- Malware and cyberattacks 15 min
- The internet, the web and IP addresses 17 min