Computer Science notes and past questions for WASSCE
Senior High · Elective · 102 resources
Free Computer Science resources for WASSCE teachers and students: notes, worksheets, flashcards, quizzes, exercises, videos, slides, revision guides, organised by syllabus topic.
Computer Science notes
- The Relational Database Model: Tables, Keys and RelationshipsHow relational databases organise data, explained step by step: why they matter for e-commerce, tables, fields and records, entities and attributes, one-to-many and many-to-many relationships, primary, foreign and composite keys; creating a database and tables in MySQL with XAMPP and phpMyAdmin, data types, and querying.Free
- E-commerce Web Page: Carts, Payments, Accounts and SecurityHow online shops work, explained step by step: shopping carts, payment gateways used in Ghana, user accounts, CAPTCHA and two-factor login, and security principles (Year 2); building a product page and connecting it to a database so products load automatically (Year 3).Free
- Building Web Pages: Editors, HTML and CSS Design ElementsHow web pages are actually written and styled, explained step by step: HTML, CSS and JavaScript (Year 1); why web development matters, static vs dynamic websites, text editors, HTML structure and tags, links, images, lists, tables, CSS (inline, internal, external), video and audio, responsive design and accessibility; code editors such as VS Code and styling a product page.Free
- Planning a Website: Outline Plans, Sitemaps, Wireframes and PrototypesHow a website is planned before it is built, explained step by step: the role of a web designer, the steps of a web outline plan (goals, user personas, categories, sitemaps, content outlines), wireframes, low- and high-fidelity prototypes, and why they save time and money.Free
- The Key Components of a Web PageHow websites are made and what a web page is built from, explained step by step: web design vs web development, front end and back end (HTML, CSS and JavaScript), hosting, URLs and browsers, and the components of a page: headings, menus, links, text, images, headers, footers, forms, buttons and widgets.Free
- Mass Storage Media: Magnetic, Optical and FlashThe three kinds of mass storage media, explained step by step so you can identify, classify and discuss them: how magnetic, optical and flash storage work, examples of each, and how to compare them by capacity, speed and cost.Free
- Conventional Systems vs Intelligent Systems: Advantages and LimitationsHow ordinary rule-following computer systems differ from intelligent systems that learn, explained step by step: what each is, Ghanaian examples, a full comparison of strengths and limitations, and hybrid systems that combine both.Free
- Artificial Intelligence: Machine Learning, Neural Networks and Natural Language ProcessingWhat artificial intelligence is and how it works, explained step by step: machine learning in everyday life; the principles and types of AI, its history, machine learning, neural networks and deep learning, natural language processing, computer vision, and real-world uses in Ghana.Free
- Machine Learning: How Computers Learn, and Tools to Try ItWhat machine learning is and how to try it yourself, explained step by step: everyday examples, supervised, unsupervised and reinforcement learning, preparing data, ML libraries, building a model with Teachable Machine and Machine Learning for Kids, and the ethics of bias, fairness, privacy and accountability; how ML fits into AI.Free
- Developing a Program in Python: Building a Simple CalculatorHow to write a real program in Python, step by step, using a calculator as the example: print, input, variables and arithmetic, turning an algorithm into code ; decisions, loops, functions, recursion and a complete calculator; functions for real problems, rounding and floating-point precision.Free
- Algorithms and the Program Development CycleHow programmers solve real-life problems step by step: what an algorithm is and its characteristics, kinds of algorithms, and the stages of the program development cycle (analysis, design, implementation, testing, documentation, evaluation and maintenance), with types of test data and errors.Free
- Main Memory: What RAM and ROM DoWhat main memory is and how it works, explained step by step: RAM and ROM, volatility, memory addresses and how memory stores bits; the features of RAM (capacity, speed and volatility) and the types DDR4, DDR5 and SDRAM.Free
- Data Structures in Real Life: Where You Meet Them Every DayWhere data structures are used in everyday technology and Ghanaian life, explained step by step: browser history, music playlists, undo buttons, print queues, search engines, social media and maps; dining-hall menus, bank queues, school charts, bus routes, student IDs and phone contacts.Free
- Types of Data Structures: Arrays, Linked Lists, Stacks, Queues, Trees, Graphs and Hash TablesEach main data structure explained step by step, with how it works and its strengths and weaknesses: arrays (1D and 2D), linked lists, stacks, queues, binary trees and graphs; trees, binary search trees, types of graphs, hash tables and maps.Free
- Data Types and Data Structures: Why Organising Data MattersWhat data types, variables and data structures are and why they matter, explained step by step: data types and variables in Python, why we use data structures, linear and non-linear, static and dynamic; data types including characters and pointers, and sequential, tree-based and graph-based structures.Free
- Data as Bit Patterns: How Computers Store Numbers, Text, Pictures and SoundHow everything in a computer, from numbers and letters to photos, music and videos, is stored as patterns of 0s and 1s, explained step by step with worked binary conversions.⚡ 5
- Computer Memory, Cache and the Memory HierarchyThe different kinds of computer memory explained step by step: flip-flops, RAM, ROM, secondary storage, cache and registers, the memory hierarchy, and browser cache, including how clearing it solves run-time problems.⚡ 5
- How a Computer Runs a Program: Von Neumann Architecture, the Machine Cycle and Embedded SystemsHow the parts of a computer work together to run a program, explained step by step: the stored-program (Von Neumann) idea, the system bus, the fetch–decode–execute–store cycle, instruction sets, and embedded systems.⚡ 5
- Boolean Expressions and Simplifying CircuitsHow to write logic circuits as Boolean expressions and make them simpler, explained step by step: notation, the identity law, De Morgan's laws, DNF and CNF, then optimising circuits, universal gates and fault-tolerant designs.⚡ 5
- Arithmetic Operations in the CPU: From Everyday Sums to Bit ShiftsHow computers do arithmetic, explained step by step: addition, subtraction, multiplication and division with their properties, PEMDAS and Python, then shift and rotation operations on binary numbers.⚡ 5
- How the CPU Adds, Subtracts and Multiplies in BinaryThe major arithmetic operations as a computer really does them, explained step by step: a recap of the operations and their properties, then repeated addition vs shift-and-add multiplication, subtraction using two's complement, and using arithmetic in Python for real problems, including floating-point precision.⚡ 5
- Computer Networks and How They WorkWhat a computer network is and how it works, explained step by step: why networks beat stand-alone computers, the components of a network, client-server and peer-to-peer architecture, cloud networks, the OSI model, wired and wireless connections, and how data travels using TCP/IP.⚡ 5
- Identifying Types of Network Systems: PAN, LAN, CAN, MAN and WANHow to recognise the main types of network system by the area they cover, explained step by step with everyday Ghanaian examples: PAN, LAN, MAN and WAN, and CANs, MANs and WANs.⚡ 5
- Differentiating LANs, MANs and WANsHow LANs, MANs and WANs differ, explained step by step: comparing area, ownership, topology, speed, fault tolerance and maintenance, comparing CANs, MANs and WANs by speed, control and links, with the devices and security each needs, and choosing between them in a design.⚡ 5
- Comparing Network Topologies: Bus, Star, Ring, Mesh, Tree and HybridThe shapes networks can take and how to compare them, explained step by step: bus, star, ring, mesh, tree and hybrid topologies and network redundancy, choosing a topology when planning a LAN, and a detailed comparison of advantages and disadvantages for network design.⚡ 5
- Categories of Computer Hardware: Input, Output, Storage and the MotherboardThe physical parts of a computer explained step by step: the five categories of hardware, common input and output devices, magnetic, optical and flash storage, and the parts of the motherboard.⚡ 5
- Barcodes and QR Codes: How They Work and Where They Are UsedHow barcodes and QR codes store information, explained step by step: types of barcodes (EAN-13, UPC-A, ITF-14, ISBN, ISSN), the structure and features of QR codes, generating and scanning them, and the input and output devices involved.Free
- Types of Software and Their FunctionsWhat software is and the different kinds of software, explained step by step: application software and system software with examples, the functions of each kind including firmware, and the categories and characteristics of system software.⚡ 5
- Installing, Configuring and Managing an Operating SystemHow to choose, install and look after an operating system, explained step by step: the parts of an OS and file systems, choosing an OS, planning and backups, the installation steps, post-installation tasks, and day-to-day and advanced management.⚡ 5
- Inside the CPU: the ALU, Control Unit and RegistersWhat the CPU is and how it works, explained step by step: its parts (Control Unit, ALU, registers, cache, clock and buses), the fetch–decode–execute–store cycle, instruction sets and embedded systems, and how registers store bits using flip-flops.⚡ 5
- Key Ideas: ISPs, Bandwidth, Internet Protocol, Subnetting and VPNsHow a network gets onto the internet and stays safe, explained step by step from Year 1 to Year 3: ISPs, bandwidth, IP addresses, TCP/IP, DNS, subnetting, VPNs, DHCP, firewalls, encryption and authentication.⚡ 5
- Network Storage: Cloud, File and Block StorageWhere a network keeps its data, explained step by step from Year 1 to Year 3: cloud storage, NAS and SAN devices, RAID, and how to back up network data safely.⚡ 5
- Communication Hardware: NICs, Modems, Routers, Switches, Hubs, WAPs and RepeatersThe devices that connect a network, explained step by step from Year 1 to Year 3: what each device does, how they work together to get you online, and the cables and wireless links they use.⚡ 5
- Designing and Planning a LANHow to design a network, explained step by step from Year 1 to Year 3: LANs, topologies and network architecture; the four principles of LAN design and the planning steps; then designing complete network systems.⚡ 10
- Characteristics of CANs, MANs and WANsNetworks of different sizes, explained step by step from Year 1 to Year 3: PAN, LAN, MAN and WAN; then CANs, MANs and WANs with their components and security; then choosing the right type when designing a network.⚡ 5
- Features of Hardware Components: The IPOSCAn introduction to the five key categories of computer hardware and the specific functions each performs within a computer system.Free
Computer Science worksheets
Computer Science flashcards
- Internet Connections and LAN Design Flashcards _Year 2ISPs, bandwidth, IP, TCP, DNS, subnetting, VPNs, LAN design and CANs.⚡ 5
- Network Design and Security Flashcards _Year 3DHCP, network layers, QoS, mesh topology, firewalls, backups and cables.⚡ 5
- Software, Operating Systems and Drivers _Year 1Application vs system software, the operating system, GUIs, RAM, multitasking, device drivers and utilities.⚡ 5
- Functions of System Software _Year 2The seven jobs of an operating system, device drivers, firmware and utilities.⚡ 5
- Operating Systems and Utility Software _Year 3Kinds and features of system software, types of operating system, CLI and GUI, and the main kinds of utility software.⚡ 10
Computer Science quizzes
- Creating a Database with MySQL · Year 3Year 3 quiz: databases, XAMPP and phpMyAdmin, MySQL and SQLite, data types, auto-increment, related tables and queries.⚡ 10
- Tables, Relationships and Keys · Year 2Year 2 quiz: what a relational database is and why it matters, tables, fields and records, entities and attributes, relationships, and primary, foreign and composite keys.⚡ 10
- Building an E-commerce Page and Connecting a Database · Year 3 building a product page with VS Code, HTML and CSS, and using PHP, XAMPP and SQL to display products from a database.⚡ 10
- Shopping Carts, Payment Gateways and User Accounts - Year 2The parts of a shopping cart, payment gateways in Ghana, user accounts, CAPTCHA, two-factor login, and security principles.⚡ 10
- HTML, CSS and Web Design Elements _Year 2static and dynamic websites, HTML structure and tags, links, images and lists, CSS methods and selectors, video, responsive design and accessibility.⚡ 10
- Outline Plans, Sitemaps, Wireframes and Prototypes _Year 1The web designer's role, web outline plans, user personas, sitemaps, content outlines, calls to action, wireframes and prototypes.⚡ 10
- Web Design, Web Development and Page Components _Year 1Year 1 quiz: web design vs development, front end and back end, HTML, CSS and JavaScript, hosting and URLs, and the components of a web page.⚡ 10
- Conventional vs Intelligent Systems _Year 3How conventional and intelligent systems work, examples in Ghana, their advantages and limitations, and hybrid approaches.⚡ 10
- Artificial Intelligence and Its Applications _Year 3Principles and types of AI, its history, machine learning, neural networks and deep learning, NLP, computer vision and real-world uses.⚡ 10
- Machine Learning, Data and EthicsWhat machine learning is, supervised, unsupervised and reinforcement learning, preparing data, ML libraries and tools, and ethics.⚡ 10
- Python Functions for Real-World Problems _Year 3Writing functions with return, converting temperatures, floating-point precision and rounding.⚡ 10
- Decisions, Loops, Functions and the Calculator _Year 2If, elif and else, for and while loops, defining and calling functions, recursion, and building a simple calculator.⚡ 10
- Python Basics: Input, Process and Outputprint(), variables, input(), converting types, arithmetic operators, comments and translating algorithms into code.⚡ 10
- Algorithms and the Program Development Cycle _Year 1Algorithms and their characteristics, the stages of the program development cycle, test data and types of error.⚡ 10
- Magnetic, Optical and Flash Storage _Year 1Identifying, classifying and comparing magnetic, optical and flash storage media.⚡ 10
- Features and Types of RAM _Year 2RAM capacity, speed and volatility, and the types SDRAM, DDR4 and DDR5.⚡ 10
- RAM, ROM and Main Memory _Year 1What RAM and ROM do, volatility, memory addresses, flip-flops, and RAM vs secondary storage.⚡ 10
- Data Structures in Everyday Ghanaian Life _Year 2Matching real-life Ghanaian examples to arrays, linked lists, stacks, queues, trees, graphs, hash tables and maps.⚡ 10
- Where Data Structures Are Used in Computing _Year 1Matching arrays, linked lists, stacks, queues, trees and graphs to their uses in computing.⚡ 10
- Trees, Graphs, Hash Tables and Maps _Year 2Parts of a tree, binary search trees, undirected, directed and weighted graphs, hash tables, collisions and maps.⚡ 10
- Arrays, Linked Lists, Stacks, Queues, Trees and Graphs _Year 1How arrays, linked lists, stacks, queues, binary trees and graphs work, with their key terms, advantages and disadvantages.⚡ 10
- Data Types and Groups of Data Structures _Year 2Integers, floats, characters, pointers and Booleans, and the sequential, tree-based and graph-based groups of data structures.⚡ 10
- Data Types, Variables and Data Structures _Year 1Data types and variables in Python, why data structures matter, linear vs non-linear, static vs dynamic, and common operations.⚡ 10
- Bits, Bytes and Binary _Year 1Bits and bytes, converting between binary and decimal, ASCII and Unicode, and how images, sound and video are stored.⚡ 10
- Memory, Cache and the Memory Hierarchy _Year 1Flip-flops, RAM and ROM, secondary storage, cache and registers, the memory hierarchy, and browser cache.⚡ 10
- Parts of the CPU _Year 1The Control Unit, the ALU, registers, cache, the clock and the buses.⚡ 10
- The Machine Cycle, Buses and Embedded Systems _Year 1The stored-program idea, the system bus, the fetch–decode–execute–store cycle, instruction sets and embedded systems.⚡ 10
- Boolean Expressions, De Morgan's Laws, DNF and CNF _Year 2Boolean notation, working out circuit outputs, the identity law, De Morgan's laws, DNF and CNF.⚡ 10
- Optimising Circuits and Fault-Tolerant Logic _Year 3Optimisation goals and techniques, universal gates, simplifying expressions, critical points, redundancy and voting circuits.⚡ 10
- Arithmetic Operations, Properties and PEMDAS _Year 2Addition, subtraction, multiplication and division, their properties, the order of operations (PEMDAS) and arithmetic in Python.⚡ 10
- Shift and Rotation OperationsLogical, arithmetic and circular shifts, the sign bit, overflow, and real-life uses of shifts.⚡ 10
- Computer Networks, Components and the OSI Model _Year 1Advantages of networks, network components, client-server and peer-to-peer, cloud networks, the OSI model and wired and wireless connections.⚡ 10
- Network Connectivity and TCP/IP _Year 2What network connectivity is, types of connection, and how TCP and IP move data across networks.⚡ 10
- PAN, LAN, MAN and WAN _Year 1Identifying personal, local, metropolitan and wide area networks from examples.⚡ 10
- CANs, MANs and WANs _Year 2Identifying campus, metropolitan and wide area networks by their area, control, speed and links.⚡ 10
- Differences Between LANs, MANs and WANs _Year 1Comparing LANs, MANs and WANs by area, examples, ownership, topology, fault tolerance and maintenance.⚡ 10
- Comparing CANs, MANs and WANsComparing CANs, MANs and WANs by area, speed, control and links, and the components and security they use.⚡ 15
- Bus, Star, Ring, Mesh, Tree and Hybrid Topologies · Year 1Year 1 quiz: the main network topologies, fault tolerance and redundancy.⚡ 10
- Comparing Topologies for Network Design · Year 3Year 3 quiz: the characteristics, advantages and disadvantages of star, bus, ring and mesh topologies, and choosing one for a design.⚡ 10
- Barcodes and QR Codes _Year 2what barcodes are, types of barcodes, QR code structure, capacity and error correction, uses, and generating codes.⚡ 10
- Application and System Software _Year 1The two categories of software, examples of application software, and the roles of operating systems, device drivers and utilities.⚡ 10
- Functions of System and Application Software _Year 2What software is, the jobs of the operating system, device drivers, firmware and utilities, and the functions of application software.⚡ 10
- Categories and Characteristics of System Software _Year 3the purpose of system software, its three categories, and its characteristics.⚡ 10
- Installing and Managing an Operating System _Year 3OS components and file systems, choosing an OS, pre-installation planning, installation methods and steps, post-installation tasks and management.⚡ 10
- Input, Output, Storage and the Motherboard _Year 1Categories of hardware, input and output devices, magnetic, optical and flash storage, and the parts of the motherboard.⚡ 10
- Shift-and-Add, Two's Complement and Python ArithmeticRepeated addition vs shift-and-add multiplication, subtraction using two's complement, and arithmetic in Python, including floating-point precision.⚡ 10
- Cyber Security Best PracticesMoMo and SIM-swap scams, phishing, strong passwords, 2FA, malware, phone safety and your rights under the Data Protection Act.⚡ 10
- Getting Online, LAN Design and CAN/MAN/WAN _Year 2Bandwidth, DNS, subnetting, VPNs, the rules of LAN design, MANs and leased lines.⚡ 10
- Designing and Securing Networks _Year 3DHCP, network layers, topologies, backups, 2FA, QoS, cables and static addresses.⚡ 10
- Website Security and Passwords _Year 2Confidentiality, integrity and availability, password hashing and salting, 2FA, encryption and the Data Protection Act.⚡ 10
- Network Storage, Devices and Network Sizes _Year 1Cloud storage, NAS, RAID, routers, switches, access points and PANs.⚡ 10
Computer Science exercises
- Python Variables, Decisions, Loops and Functions _Year 2Variable names, if/elif/else, tracing a loop and writing a function. Get feedback from Tudi AI or a tutor.⚡ 15
- LAN Design, Subnetting and WANs _Year 2the four rules of LAN design, subnetting, VPNs and a bank WAN. Get feedback from Tudi AI or a tutor.⚡ 15
- IP Addressing and Designing a Network _Year 3Static and dynamic IP addresses, designing a school network and choosing topologies. Get feedback from Tudi AI or a tutor.⚡ 15
- Python for Real-Life Problems _Year 3Temperature conversion, decimal rounding errors and a mobile money fee program. Get feedback from Tudi AI or a tutor.⚡ 10
- Algorithms, Pseudocode and Flowcharts _Year 1What an algorithm is, pseudocode, flowchart symbols and the program development cycle. Get feedback from Tudi AI or a tutor.⚡ 10
- Network Devices, Storage and Network Types _Year 1Switches vs hubs, LAN/MAN/WAN and cloud storage. Get feedback from Tudi AI or a tutor.⚡ 10