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

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?

Video

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.

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.

Video

Area of a square and a triangle

Do you know the formula for working out the area of a square? How about a triangle? Watch this short maths video to learn the formulas for both.

Video

Catalyst: Probability and the gambler's fallacy

Mathematician Lily Serna visits Luna Park to explain a great probability pitfall. She shares a century-old tale from Monte Carlo casino, and then she puts its lesson to the test. If you flip a coin and it lands on heads three times in a row, what result would you predict for the next flip? Find out why intuition might land ...

Video

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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MathXplosion, Ep 8: Birthday probability

What is the probability there are at least two people in your class who have the same birthday? If you have at least 23 people in your class, the chances are good. Find out the maths behind this theory.

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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?

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.  

Video

Catalyst: Probability and the birthday paradox

Even when a maths problem seems simple – for example, the chance of two people sharing a birthday – the maths can run counter to our human intuition. Mathematician Lily Serna poses a maths problem to the Clovelly Bowling Club: how many people do you need to gather to get a 50 per cent chance of any two people in that group ...

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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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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

Maths inside bees and beehives

Bees are necessary for assisting many plants to produce the food we eat, including meat and milk. Colony collapse disorder, which describes the disappearance of beehives, could have catastrophic effects on food production. Australian scientists are applying their maths and science knowledge to build up a picture of a healthy ...

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 ...

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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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Mean, median and mode

This resource is a video demonstration, with audio commentary, about calculating the mean, median and mode of a data set. The meaning of each of the terms - mean, median and mode - is explained and the difference between them is clarified. The resource explains the process and demonstrates a handwritten method for calculating ...

Video

The amazing 'angle-a-tron'

Lost your protractor? Well, find out how to make an 'angle-a-tron'. This might just be the coolest mathematical tool you've ever used. Measure all sorts of angles. It's easy with an angle-a-tron!

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MathXplosion, Ep 10: What is the strongest shape?

Are triangles really the strongest shapes ever? If so, why? Learn how and why right-angled and equilateral triangles have been used in engineering, architecture and design through the ages.

Video

Numbers Count: What are factors?

What are factors? Watch as the jelly babies in this clip show you! What are the factors of 12? How many factors does the number 11 have? Try explaining to a friend what a prime number is.

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.