SS 1 First Term

Lesson objectives

By the end of the week, learners should be able to:

1. Sequence eight early computing devices from the abacus to the microprocessor.
2. State the contribution of Pascal, Babbage, Lovelace and Hollerith.
3. Name the five computer generations and the main technology of each.
4. Compare the first and fourth generations on size, speed and heat.
5. Explain why transistors replaced valves and valves gave way to integrated circuits.

Key vocabulary

• Abacus: a counting frame with beads used for arithmetic.
• Napier's bones: numbered rods for multiplication and division.
• Pascaline: Blaise Pascal's geared adding machine.
• Analytical Engine: Charles Babbage's programmable mechanical design.
• Lovelace: Ada Lovelace, first programmer credited with the Analytical Engine.
• Hollerith: Herman Hollerith's punched-card tabulator.
• Valve: an early electronic switching component that was large and hot.
• Transistor: a small solid-state switch replacing the valve.
• Integrated circuit: many transistors on one silicon chip.
• Microprocessor: a complete processing unit on a single chip.

Common misconceptions

• "The abacus was the first computer." The abacus is a calculating aid without automatic processing.
• "Babbage built the Analytical Engine." Babbage designed it but did not build it in his lifetime.
• "Generations are measured only by years." Generations define the dominant electronic technology.

Teacher activities

1. Starter: ask learners to multiply 27 times 13 on the abacus without paper.
2. Walk through early devices in date order and state each inventor's contribution.
3. Present the generations table with the period, technology and example machine for each row.
4. Show images of valve, transistor, integrated circuit and microprocessor machines.
5. Model why transistors replaced valves and integrated circuits replaced transistors.
6. Close with the exit question comparing first and fourth generation machines.

Student activities

1. Attempt the multiplication on the abacus and compare with mental math.
2. Copy the device list and add the contribution of each inventor.
3. Complete the generations table for rows 2 through 5.
4. Rank the five generations from largest to smallest and fastest to slowest.
5. Write two sentences explaining why transistors replaced valves.
6. Answer the exit question in one sentence about the fourth generation.

Practical / learning evidence

A five-row generations table with columns Generation, Period, Main technology, Size, Speed/Heat and Example machine. Plus a dated device list of eight entries from the abacus to the microprocessor. Hand in both for marking.

Resources and preparation

A bead frame or printed abacus, a valve photograph, a transistor, an integrated circuit and pictures of ENIAC, a 1980s PC and a modern phone. Offline route: invention cards arranged in date order, no device needed. Handle any glass valve carefully and keep it out of learners' reach.

Assessment for learning

Inspect the generations table for at least one correct example machine per generation. Ask two learners to defend their ranking of sizes. Mark the device list for correct date order. Record any learner who writes "the first computer was ENIAC."

Inclusion and homework

Provide the generations table partly completed for learners who need scaffolding. Allow extra time on the timed drill where approved. Extend confident learners with predicting the sixth generation. Homework: ask an older family member which computer they first used and write three sentences about how it differs from today's phone.