SS 3 First Term

Learning Objectives

• Revise all topics of the term.
• Consolidate programming and data structures.
• Practise databases, networks and web development.
• Prepare for the end of term examination.

Review of Computational Thinking and Programming

Computational thinking uses decomposition, pattern recognition, abstraction and algorithms. A problem is analysed and a requirements document is drafted before any code is written.

A program is built from sequence, selection and iteration. Functions and modules keep code organised, and a consistent style makes it easy to read. Data structures such as arrays, lists, records, trees and graphs decide how well data can be stored and used.

Object-oriented programming groups data and behaviour into classes. Encapsulation, inheritance and polymorphism allow large programs to be built and changed with less risk.

Review of Databases and Networks

A database is an organised store of related data managed by a DBMS. SQL is used to read, write, update and delete records, and keys connect tables. An entity relationship diagram shows how the tables relate.

A network connects devices so they can share data. Networks are classified by area and by topology, and devices such as switches, routers and firewalls control the traffic. IP addresses and DNS identify devices and names, and protocols carry the data.

The web is built on HTML for structure and CSS for style. Pages are stored on a host and reached through a domain name, and server side code works with a database.

Review of the SDLC and Security

The software development life cycle runs from planning and analysis through design, implementation and testing to deployment and maintenance. Waterfall and agile are two common models, and testing and documentation run through the project.

Cyber security protects systems and data. Encryption, firewalls, strong passwords and regular updates reduce risk, and the CIA triad states the goals of confidentiality, integrity and availability.

Emerging digital technologies such as artificial intelligence, cloud computing and the internet of things change how people work, and each brings both benefits and risks.

Practical Work

1. Write a function that searches a list for a value.
2. Write a SELECT statement with a WHERE clause.
3. Draw a labelled star network and name each device.
4. Write a small HTML page with a heading and a list.

Scenario-Based Questions

1. Explain how you would revise ten weeks of senior work before an examination.
2. A learner mixes up a primary key and a foreign key. Explain the difference.
3. A school is choosing waterfall or agile for a new system. Recommend one and justify it.
4. Explain how encryption protects data on a network.
5. Explain one benefit and one risk of using artificial intelligence.

Examination and Continuous Assessment Practice

These questions are taken from the First Term examination and Continuous Assessment papers for this class. Answer them in full sentences.

1. A team must build a lost-and-found app, but the work is too large for one person. Explain computational thinking, and describe the four pillars the team would apply to this problem.
2. (a) Define a Database Management System (DBMS) and state two (2) advantages of databases over traditional file systems. (b) Explain the following database terms: (i) Record (ii) Field (iii) Primary Key (c) A database backup file measures 5 Gigabytes (GB). Convert this capacity into Megabytes (MB) and calculate how many 4 MB database tables can fit into that storage space. Show workings.
3. (a) Define a Computer Network and list three (3) classifications based on geographical coverage (LAN, MAN, WAN). (b) Compare and contrast Bus Topology and Star Topology in computer networking. (c) A network data transmission channel operates at a speed of 16 Megabits per second (Mbps). Calculate how many Megabytes (MB) of data are transferred across this channel in 15 seconds. Show all steps.
4. (a) Differentiate between a Web Browser and a Search Engine, giving two (2) popular examples of each. (b) Explain what a URL is and describe its main components when accessing web pages. (c) A web page cache folder contains 2,048 Kilobytes (KB) of data. Convert this storage size into Megabytes (MB) and further convert it into bits. Show complete calculations.
5. (a) What is Cybersecurity? State three (3) common computer security threats or malware types. (b) Explain the protective roles of Antivirus software and Firewalls in defending computer networks. (c) Perform the following storage scale conversions, showing all intermediate steps: (i) Convert 2 Terabytes (TB) into Gigabytes (GB). (ii) Convert 4,096 Megabytes (MB) into Gigabytes (GB). (iii) Arrange the following storage capacities in descending order: 16,384 Bits, 2 MB, 1,024 KB, 3 GB.
6. A school is designing a system that stores pupils' names and grades, and a security officer explains that security must be designed in from the start. Explain the CIA triad, the controls that protect each element, and give an example of a breach of each.
7. Before structured programming, a program was full of unpredictable jumps that made it costly to fix. Explain what structured programming is, name its three control structures, and give a situation in which each is used.
8. A pupil discovers that every student in the school can see the entire marks sheet. Explain the element of the CIA triad that has failed, state how it should have been protected, and write the matching security requirement for the requirements document.

LEARNING OBJECTIVES: BY THE END OF THE LESSON STUDENTS SHOULD BE ABLE TO:

Rationale: Computational thinking uses decomposition, pattern recognition, abstraction and algorithms. Understanding review of Computational Thinking and Programming, review of Databases and Networks, review of the SDLC and Security helps learners use digital technology confidently, safely and responsibly.

Pre-requisite Knowledge: In Week 10, learners studied Cyber Security and Emerging Digital Technologies, including the Parts of Computer Security, threats to Computer Security, protecting the Computer. The knowledge from that week is used again in this lesson.

Learning Material/Teaching Aid: Whiteboard, markers, computer or laptop where available, printed notes and charts on Revision, practical task sheets, learners' notebooks and pens.

Reference Materials: Digital Technology for Senior Secondary Schools (SS 3); NERDC Digital Technology Curriculum; Digital Technology SS 3 First Term Notes (Week 11); First Term examination and Continuous Assessment question papers.

LESSON DEVELOPMENT

Assignment: i. (a) Define a Computer Network and list three (3) classifications based on geographical coverage (LAN, MAN, WAN). (b) Compare and contrast Bus Topology and Star Topology in computer networking. (c) A network data transmission channel operates at a speed of 16 Megabits per second (Mbps). Calculate how many Megabytes (MB) of data are transferred across this channel in 15 seconds. Show all steps. ii. Explain how you would revise ten weeks of senior work before an examination.