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Grade 8 revision notes and worked examples

Use these notes to understand a method before testing yourself. Read an example, try it without looking, then explain the steps in your own words.

Written by QuizChallenge SA · Updated 29 September 2026 · 95 questions available for this grade

Like terms, equations and right triangles

Combine algebraic terms only when their variable parts match. In 4x + 3 − x + 5, the x terms give 3x and the constants give 8, producing 3x + 8. Solve equations by performing equivalent operations on both sides. For right triangles, Pythagoras relates the squares of the two legs to the square of the hypotenuse.

Worked example or application

If the legs are 6 cm and 8 cm, c² = 36 + 64 = 100, so c = 10 cm. The value 100 is the square of the length, not the length itself.

Common mistake: Pythagoras applies to right triangles. Identify the hypotenuse opposite the right angle before substituting.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Cells and energy transfer

Cells are basic structural units of living organisms. Structures have functions: a membrane controls movement across the boundary and a nucleus contains genetic information in most familiar plant and animal cells. Energy transfers through systems rather than appearing from nowhere. In food chains and electrical or heating systems, trace where energy enters, how it is transferred and what forms are produced.

Worked example or application

A lamp transfers electrical energy into light and thermal energy. Describing only the light misses another output. Similarly, a consumer gains energy by eating organisms, rather than producing it independently.

Common mistake: Avoid treating every cell as identical. Plant and animal cells share features but differ in important structures.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Climate, settlement and transport connections

Compare climate information using units and the time period represented. Temperature and rainfall patterns help explain environments but do not determine every human activity. Settlement and transport are linked: routes connect homes, jobs and services, while growing settlements can create demand for more transport. A useful explanation connects the evidence to the process rather than simply naming a place.

Worked example or application

A road connecting a settlement to markets can improve access for people and goods. This may influence growth, but costs, land availability and other conditions also matter.

Common mistake: Do not use one day’s weather as proof of a place’s long-term climate.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Industrial change and colonial expansion

When studying industrialisation, distinguish invention, production changes and their effects on people. Factories and new transport methods altered work and settlement, but experiences varied between owners, workers and communities. Colonial expansion should likewise be examined through motives, methods and consequences for different groups. Connect dates to processes instead of learning dates as isolated facts.

Worked example or application

A steam engine is not a complete explanation of industrialisation. Ask how energy, labour, resources, capital and markets worked together, and what changed for the people involved.

Common mistake: A cause can contribute to an event without being its only cause. Support explanations with specific evidence.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Inference, persuasion and language effects

In a complex sentence, a subordinate clause depends on a main clause. In advertisements, examine claims, emotional appeals and omissions. A statement such as “Everyone smart buys this” pressures the reader to identify with a desirable group without proving the product is better. Figurative language and connotation create effects that should be explained in their context.

Worked example or application

“The wind whispered” gives a human action to the wind: personification. In “Although it was late, we finished”, the although-clause supplies a contrast but cannot stand as the complete main message alone.

Common mistake: An advertisement’s popularity is not evidence that every claim in it is true.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Production factors and the accounting equation

Production uses natural resources, labour, capital and entrepreneurship. Capital equipment is produced machinery or tools, while entrepreneurship organises resources and accepts risk. In accounting, assets = equity + liabilities. The owner’s contribution is capital, not sales revenue. Recording cash receipts and payments separately helps identify where money comes from and how it is used.

Worked example or application

If assets are R9 000 and liabilities R3 000, equity is R6 000. If an owner contributes R2 000 cash, both the cash asset and equity increase by that amount.

Common mistake: Do not count the owner’s investment as income earned from customers.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Gears, pressure and communicating designs

Meshing gears turn in opposite directions. A smaller driver turning a larger driven gear reduces output speed while increasing torque under suitable conditions. Hydraulic systems use pressure transmitted through a confined liquid; pneumatic systems use gas. Drawings communicate dimensions and assembly, and an exploded view separates parts to show how they fit together.

Worked example or application

A 10-tooth driver paired with a 30-tooth driven gear makes three turns for one driven turn. The driven gear’s speed is one third of the driver’s. This is a speed–torque trade-off, not free energy.

Common mistake: Mechanical advantage does not create energy. Friction and other losses affect real systems.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Depth, emphasis and coordinated performance

Overlap, relative size and placement can suggest depth in a flat image. A focal point draws attention through contrast or emphasis. In drama, blocking organises positions and movement on stage. In dance, unison means performing the same movement together. In music, dynamics concern loudness, while tempo concerns speed. Keep these concepts distinct when describing an effect.

Worked example or application

A louder musical phrase changes dynamics but need not change pitch or speed. Dancers performing a phrase at the same time are in unison; starting at different times creates a different relationship.

Common mistake: Describe the observed choice first, then explain its possible meaning. Do not substitute personal preference for evidence.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Self-motivation and informed responses to influence

Media, friends and family can influence self-concept. Critically assess comparisons rather than accepting every image as everyday reality. Constructive self-motivation includes changing a method after a setback and seeking help. Assertiveness expresses boundaries firmly without threats. For unfamiliar online challenges, assess risks and sources before participating. Popularity is not a safety assessment.

Worked example or application

A useful response to a disappointing result is “I will check which errors were misunderstandings and which were careless reading.” It identifies action instead of defining the learner as a failure.

Common mistake: Positive self-talk should be realistic. “I can improve with practice” is more useful than promising never to make a mistake.

Check your understanding: Cover the example and explain its reasoning. Change one detail and consider how the answer would change.

Practise Grade 8

Choose from Creative Arts, Economic and Management Sciences, English, Geography, History, Life Orientation, Mathematics, Natural Sciences, Technology. Social Sciences is separated into Geography and History practice in Grades 6–9. Your school timetable may include other languages or electives.

Start Grade 8 practice

How to use these notes responsibly

Use your teacher’s current term plan and textbook to check what you need to cover. These notes select concepts for practice; they do not replace lessons, practical tasks, essays or examination preparation. Examples with financial rates are hypothetical unless clearly identified otherwise.

Official reference: Department of Basic Education annual teaching plans for this phase. Check the DBE’s published documents and your school’s guidance for the required sequence and depth.

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