JSS 3 First Term

Learning Objectives

• Revise every topic of the First Term.
• Practise questions on networks, number systems and programming.
• Identify and settle weak areas before the examination.
• Plan the final week of revision.

Review of Networks and the Internet

A network is two or more devices connected so they can share resources. Networks are named by the area they cover: a PAN around one person, a LAN in one building, a MAN across a city and a WAN across a country or the world. The internet is the largest WAN.

The key devices are the network interface card, the hub, the switch, the router, the modem, the access point and the firewall. Data moves in packets, and the protocols TCP/IP, HTTP, HTTPS and DNS decide how those packets are addressed, moved and secured.

Digital safety is part of the topic. Passwords are kept private, unknown links are not clicked, and https is used for any page that takes personal data.

Review of Number Systems and Data Representation

A number system is built on a base. The decimal system is base 10, the binary system is base 2, the octal system is base 8 and the hexadecimal system is base 16. The value of a digit depends on its place value.

To change a binary number to decimal, add the place values above each 1. To change a decimal number to binary, divide by 2 and read the remainders from bottom to top. To change binary to hexadecimal, group the bits in fours and replace each group.

All data is stored in binary. Text is stored through codes such as ASCII and Unicode, images through the colour numbers of each pixel, and sound through samples taken many times a second. The units of data grow from the bit to the byte, the kilobyte, the megabyte, the gigabyte and the terabyte.

Review of Logic, Algorithms and Programming

A logic gate takes one or more bits and gives one bit. The AND gate needs both inputs to be 1, the OR gate needs at least one, and the NOT gate flips its single input. Every gate can be shown in a truth table.

An algorithm is a step by step plan. It is clear, finite and effective. A flowchart shows an algorithm with the oval, the rectangle, the parallelogram and the diamond joined by arrows.

A program is an algorithm written in a language a computer can run. Most programs follow the input, process and output model. An error in a program is a bug, and finding and fixing it is called debugging.

Answering Examination Questions

Objective questions reward accuracy, so read every option before choosing. Short answer questions reward precision, so give exactly what is asked. In a difference question write both parts in the order asked. In a list question number each item so that it can be marked.

In a calculation, show the working even when the answer is correct, because method earns marks. In a diagram, label every part clearly.

Plan the last week of revision. Spend more time on the topics that were weakest in the class test, and end with a light review the evening before the paper.

Practical Work

1. Write the four network types and one example of each from memory.
2. Convert 1101 to decimal and 13 to binary without looking at your notes.
3. Draw the truth tables for AND, OR and NOT from memory.
4. Write the algorithm for a simple everyday task in five steps.

Scenario-Based Questions

1. Explain how you would revise nine weeks of work in four evenings.
2. Explain why reading notes once is a weak method of revision and give a better method.
3. A learner mixes up a switch and a router. Explain the difference between the two.
4. A learner says binary 10 equals decimal 10. Correct the learner.
5. Describe how a program plan differs from the finished program.

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. Three classmates each hold a document on a phone and want every one of them to have all three documents. Define a computer network, state the devices on a network are called, give the reasons networks are set up, and explain how a school network meets the classmates' need.
2. (a) Define Digital Citizenship and state three (3) qualities of a good digital citizen. (b) Explain the term Digital Footprint and how students can maintain a positive online reputation. (c) Mention two (2) dangers of unsafe online behaviors (e.g., cyberbullying or sharing personal data).
3. A pupil connects a Bluetooth headset to a phone, a school laboratory has 30 computers sharing one printer, a university links campuses in different parts of Abuja, and the whole world is linked together. Classify each of these four situations as a PAN, LAN, MAN or WAN, and give the meaning of each term.
4. A learner says the internet and the World Wide Web are the same thing, and another says Wi-Fi is the internet. Define each of the three terms, explain the difference between the internet and the web, and correct the two statements.
5. A school wants a reliable, high-speed connection that many computers can use, and it must pay for the service. Explain what the internet is, name the services it carries, define an Internet Service Provider, and explain how a school chooses and pays for its connection.
6. A community centre wants internet, and a pupil at home already has wireless access. Name the means of accessing the internet, and explain the difference between Wi-Fi and the internet.
7. A learner searches for information and finds thousands of results, some of them advertisements. State how a learner should search safely, and the questions a learner should ask in order to judge a web page before trusting it.
8. A learner sends a photograph from a phone to a printer in another building, and the network must deliver it. State the steps data follows as it travels across a network, define the terms sender, receiver, medium and node, and compare a client-server network with a peer-to-peer network.