Close message Due to scheduled maintenance on Thursday 10th September 2026 between 5:00 pm until 7:00 pm AEST, Scootle may face a disruption in service. We apologise for any inconvenience caused.

Mathematics / Year 8 / Algebra

Curriculum content descriptions

create, expand, factorise, rearrange and simplify linear expressions, applying the associative, commutative, identity, distributive and inverse properties (AC9M8A01)

Elaborations
  • rearranging and simplifying linear expressions involving variables with integer coefficients and constants; using manipulatives such as algebra tiles to support calculations; for example, using manipulatives to demonstrate that \(2x+4\;=\;2(x+2),\;3(a-b)=3a -3b\), or \(5(m+2n)+3m-4n\;=\;5m+10n+3m-4n\;=\;8m+6n\)
  • demonstrating the relationship between factorising and expanding linear expressions using manipulatives, such as algebra tiles or area models, and describing with mathematical language
  • using the distributive, associative, commutative, identity and inverse properties to expand and factorise algebraic expressions using strategies such as the area model
General capabilities
  • Critical and creative thinking Critical and Creative Thinking
  • Numeracy Numeracy
ScOT terms

Distributivity,  Mathematical expressions,  Simplification (Algebra),  Number operations

Text

The Geometry and Algebra of Honeycomb - Calculate

This integrated unit of work explores the amazing structures of honeycomb by examining the properties of regular and irregular polygons and polyhedra. Students then move on to solve problems using geometric and algebraic reasoning.

Text

Linear Relationships (and how Maths can help you choose a great car) - Calculate

The activity has students collecting their own information from a well-known Australia car buying website and using this to find an estimated relationship between the ‘asking price’ for a used car and the distance it has traveled in kilometres.

Downloadable

Algebra: Foundation to Year 9

This comprehensive resource describes the progression of algebra-related ideas and algebraic thinking. The resource demonstrates examples of relevant teaching strategies, investigations, activity plans and connected concepts in algebra including teaching and cultural implications.

Text

reSolve: Quarter Cartons

This lesson challenges students to use algebra and proportional reasoning to investigate how changing the size of a paper square or rectangle impacts the dimensions of a box folded from that paper. Students apply knowledge about nets of 3D objects and explore algebraic relationships through a set of hands-on activities ...

Text

reSolve: Polygon Pieces

This lesson explores the geometry of cutting polygons in different ways and using algebra to express subsequent findings. Students use one straight cut to divide a convex polygon into two new polygons. They make generalisations about the total number of sides of the two new polygons, and about the number of different combinations ...

Text

reSolve: Algebra: Tens and Units

This sequence of lessons aims to develop understanding of algebra as generalised arithmetic. Students learn to express 2- and 3-digit numbers in a general form and use this to explain results of arithmetic operations involving numbers with their digits reversed. The task links the ideas of place value with algebraic reasoning. ...

Text

reSolve: Algebra: Think of a number - Linear Equations

This lesson explores algebra by generalising results from arithmetic used in 'think of a number' games. Students connect arithmetic operations with algebraic notation and visualisations. The lesson begins with an observation made using arithmetic that students then justify and extend using algebra. The lesson is outlined ...

Text

reSolve: Algebra: Addition Chain

This sequence of lessons explores making algebraic generalisations of sequences. Students use spreadsheets to investigate potential arithmetic relationships and then use algebra to identify and justify which relationships are generally true. The task can be used as a springboard for an in-depth exploration of the Fibonacci ...

Text

reSolve: Working with algebra

This sequence of two lessons gives students opportunities to explore and share strategies for solving algebraic problems. The lessons focus on open-ended problem solving and developing multiple approaches to solving problems algebraically such as using like terms and substitution. Students work individually and in small ...

Text

Algebraic expressions

This is a website designed for both teachers and students that addresses algebraic expressions from the Australian Curriculum for year 8 students. It contains material on using simple positive and negative fractions, substitution, collecting like terms, taking products, and expanding brackets using the distributive law ...

Text

reSolve: Fibonacci Miles

This lesson introduces students to a trick for quick conversion between miles and kilometres using the Fibonacci sequence. Students are challenged to explain why the trick works. They investigate using their knowledge of ratio and discover that the miles/kilometres conversion rate is close to the golden ratio. The lesson ...

Text

reSolve: Mathematical modelling: Screentime footprint

In this sequence of four tasks students use linear models to investigate how screen time contributes to carbon dioxide emissions. They consider their personal digital footprint and make predictions about future emissions. Key learning goals, pedagogical tools, illustrations of practice and design decisions for teachers ...

Video

Proportional reasoning video

Use this video as a springboard to explore scaling or proportional thinking, and to apply that thinking in a food context, drawing on reasoning and mathematical modelling.

Video

MathXplosion, Ep 50: How to use a tetrahedron to solve the tree problem

How can you place four trees exactly the same distance apart from one other? By making a model! By using miniature trees to make a model of the problem, it becomes clear that a 2D solution is impossible. We learn how objects can help us visualise the problem situation, which in this case requires a 3D solution: a tetrahedron.

Video

MathXplosion, Ep 1: Magic 9s

Follow these simple calculations to illustrate the special properties of the number 9. Pick your favourite number between 1 and 9 and multiply that number by 3. Add 3 to your answer. Multiply the result by 3. Treat your two-digit answer as two separate numbers and add them together. No matter what number you pick to start ...

Video

What are pixels?

Meet Kevin Systrom and Piper Hanson as they explain how digital images work. What are pixels, those tiny dots of light, made from? How are colours created and represented? What does Kevin say about the way mathematical functions are used to create different image filters. What is the difference between image resolution ...

Video

My Five Cents: What is opportunity cost?

What is the true cost of buying something? Gen Fricker explains that it's more than just money. Learn about opportunity cost - what it is, why it's a helpful tool and when to use it. Simple! Then test yourself with ASIC MoneySmart's "Things to think about" classroom exercises.

Video

BTN: What is the GST?

The Goods and Services Tax (GST) is a tax placed on things people buy with money or things people do for money. Can you name some goods and services that have GST? What about some goods and services that don't have GST? Find out when and why the GST was first introduced.

Video

Catalyst: Take the Phi Golden challenge

The golden ratio, Phi: fact or fallacy? What about the Fibonacci sequence? We are told this ratio and its cousin Fibonacci occur everywhere in nature. Let's see which of these claims stacks up when put to the test.

Video

My Five Cents: Why borrowing can cost you more

Think credit cards are basically free money? Gen Fricker will make you think again. Learn how interest rates and fees affect the money you borrow, and why they may be more expensive in the long run. Oh dear! Then test yourself with ASIC MoneySmart's "Things to think about" classroom exercises.