Mathematics / Year 7 / Algebra

Curriculum content descriptions

recognise and use variables to represent everyday formulas algebraically and substitute values into formulas to determine an unknown (AC9M7A01)

Elaborations
  • linking variables to attributes and measures being modelled when using formulas, such as the area of a rectangle is equal to the length x width as \(A\;=\;l\;\times\;w\) or using \(p\;=\;6g\;+\;b\) to describe a total of points expressed as goals (worth \(6\) points) and behinds (worth one point)
  • interpreting and using formulas obtained from other sources; for example, maximum heart rates and target heart rates for moderate exercise
  • substituting numerical values for variables when using formulas and calculating the value of an unknown in practical situations; for example, calculating weekly wage \(W\) given base wage \(b\) and overtime hours \(h\) at \(1.5\) times rate \(r\), \(W\;=\;b+1.5\times h\times r\), using values for mass \(m\) and volume \(v\) to determine density \(d\) of a substance where \(d\;=\;\frac mv\)
  • using everyday formulas and their application to contexts on Country/Place, investigating the relationships between variables
General capabilities
  • Critical and creative thinking Critical and Creative Thinking
  • Numeracy Numeracy
ScOT terms

Substitution,  Variables (Mathematics),  Equations

Video

Algebra basics video

Use this video as a springboard to introduce algebraic thinking, and to apply that thinking to a financial context, drawing on reasoning.

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Patterns, primes and Pascal's Triangle

Are you intrigued by patterns? Check out Vi Hart as she explains how to visualise patterns in prime numbers, using Ulam's Spiral. Watch as Vi creates patterns, using Pascal's Triangle to explore relationships in number. See what happens when she circles the odd numbers. What rule does she use to create the final pattern?

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MathXplosion, Ep 22: How to communicate numbers with Roman numerals

Explore an alternative way to communicate numbers using the anchor numbers 5 and 10 and the ancient Roman counting system based on letters. Roman numerals were used throughout Europe well into the middle ages and still appear in the names of monarchs, the production year of films, on buildings and on timepieces.

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MathXplosion, Ep 17: Develop mathematical mind-reading skills

Amaze your friends with your super mind-reading skills. Here’s a brain game you can play by asking a few questions and substituting letters for numbers! Learn to follow a specific sequence of arithmetical steps to always arrive at the same answer.

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Can you guess the weight of Uluru?

What is the "wisdom of a crowd"? Mathematician Lily Serna investigates a mathematical phenomenon that suggests that if you have a large enough crowd, with a broad variety of people making estimates, then the mean (average) answer of the crowd will be accurate! Find out if a crowd can guess the weight of Uluru from the ground ...

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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.  

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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.  

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MathXplosion, Ep 7: The power of exponents

Have you heard of the term "exponential growth"? Growth can occur very quickly when powers are involved. See how you can use the power of two to rapidly increase the amount of anything from grain to coins!

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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.

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Solving percentage problems

This digital resource is a video demonstration of a procedural method to calculate an unknown quantity, given an amount is a known percentage of the unknown. For a single example, students are presented with an algorithmic, step-by-step, pen-and-paper method. The demonstration is complemented by the presenter's commentary ...

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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 ...

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Working out the areas

Do you know how to work out the area of a square, a rectangle or a triangle? Learn the simple maths formulas needed from this video. What would be the area of a rectangle with a height of 5cm and a length of 3cm?

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How does income tax work?

Gen Fricker makes income tax interesting! Learn about income tax - what it is, how it works and when you have to pay it. Easy-peasy! Then test yourself with ASIC Moneysmart's "Things to think about" classroom exercises.

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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.

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MathXplosion, Ep 11: Fun facts about the number seven

Did you know that the digits on opposite faces of dice will always add up to seven? Use dice as fun tools to reinforce fact families of seven, multiples of seven and subtraction skills.

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Catalyst: Small scale measurements

What units of measurements do we use to describe incredibly small things like blood cells and atoms? Watch as you are taken on a journey to explain the different units of measurement that we use to describe the very small.

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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.

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Types of triangles

What is the difference between equilateral, isosceles and scalene triangles? See if you can find and classify triangles based on the definitions given in this maths video.

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MathXplosion, Ep 49: The probability of finding matching socks

Check out this probability puzzle that requires you to weigh all the possibilities. Pick the most likely outcome when confronted with a drawer full of loose, unpaired socks! How did Eric come up with a matching pair?

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MathXplosion, Ep 40: Kaprekar's operation

Did you know that 6,174 is a very mysterious number? In 1949, the mathematician Dr Kaprekar from India devised a process now known as Kaprekar's operation. First, choose a four-digit number where the digits are all different. Then rearrange the digits to get the largest and smallest numbers these digits can make. Finally, ...