Mathematics / Year 9 / Number and Algebra / Real numbers

View on Australian Curriculum website Australian Curriculum, Assessment and Reporting Authority
Curriculum content descriptions

Solve problems involving direct proportion. Explore the relationship between graphs and equations corresponding to simple rate problems (ACMNA208)

Elaborations
  • identifying direct proportion in real-life contexts
General capabilities
  • Literacy Literacy
  • Numeracy Numeracy
  • Critical and creative thinking Critical and creative thinking
ScOT terms

Rates (Ratios),  Linear equations,  Direct proportions,  Gradients

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Year level 9-10
Resource type
Learning area Mathematics
Interactive resource

In proportion: variables in ratios

Complete customer orders for a large hardware store by interpreting the ratios. Work in the gardening department to fill orders for liquid fertiliser (expressed as ratios). Examine the equations suggested to you by your colleagues. Choose and solve the correct equation to complete each order. This learning object is the ...

Interactive resource

Mobile phone plans: several companies

Compare monthly call costs quoted by different phone companies. Use line graphs to work out the costs for talk time, text messages, photos and total costs. Recommend the best plan. This learning object is one in a series of six objects.

Interactive resource

In proportion: graphs of ratios, rates and scales

Complete customer orders for a large hardware store by interpreting ratios, rates and scales. Work in the manager's office and discover how ratios, rates and scales can be represented as graphs. Use the graphs to discover quantities for garden fertiliser ingredients, the cost of mulch, and for finding lengths of timber ...

Interactive resource

In proportion: rates and scales

Complete customer orders for a large hardware store by interpreting the rates and scales. Work in the gardening department to fill orders for mulch (expressed as rates) and help out with scale plans in the timber department. Use the machine to set the rates, create the right amounts and deliver the mulch. Use the scale ...

Interactive resource

Mobile phone plans: find the best deal 1

Help three customers compare monthly call costs quoted by two different phone companies. Use line graphs to work out the costs for talk time, text messages and total costs. Recommend the best plan. This learning object is one in a series of six objects.

Teacher resource

MoneySmart: How can we obtain more money?

This is a year 9 mathematics unit of work about making money. Intended to take about ten hours, the unit consists of six sets of student tasks supported by teacher notes. Tasks include investigating part-time work; surveying class members about the hours they work; using a spreadsheet; calculating earnings and interest; ...

Interactive resource

Mobile phone plans: peak and off-peak

Compare monthly call plans quoted by a phone company. Look at the effect of off-peak discounts. Use line graphs to work out the costs for talk time, text messages, photos and total costs. Recommend the best plan. This learning object is one in a series of six objects.

Interactive resource

In proportion: ratios

Complete customer orders for a large hardware store by interpreting the ratios. Work in the gardening department to fill orders for fertiliser, to the strength requested by customers. You will need to set ratios for water:concentrate. Use the machine to set the ratios, create the right amounts and mix the fertiliser. Explore ...

Interactive resource

Mobile phone plans: find the best deal 3

Help three customers compare monthly call costs quoted by three different phone companies: Dialo, Airplay and Jump. Use line graphs to work out the same company and standard rates for talk time, text messages, photos and total costs. Recommend the best plan. This learning object is one in a series of six objects.

Interactive resource

Mobile phone plans: find the best deal 2

Help three customers compare monthly call costs quoted by three different phone companies: Orbit, Presto and Kool. Use line graphs to work out the costs for talk time, text messages, photos and total costs. Recommend the best plan. This learning object is one in a series of six objects.

Video

Using linear equations to model population growth, Hooke's Law and parcel shipping charges

In this animated presentation students are provided with three examples of mathematical modelling in real-world settings. Linear functions are used to model population growth, Hooke's Law and parcel shipping charges.

Interactive resource

In proportion: variables in rates and scales

Complete customer orders for a large hardware store by interpreting rates and scales. Work in the gardening department to fill orders for mulch (expressed as rates), and help out with scale plans in the timber department. Examine the equations suggested to you by your colleagues. Choose and solve the correct equation to ...

Interactive resource

Mobile phone plans: one company

Compare monthly call plans quoted by a phone company. Use line graphs to work out the costs for talk time, text messages, photos and total costs. Recommend the best plan. This learning object is one in a series of six objects.

Interactive Resource

Syllabus Bites: Proportionality problems

This is the fourth in a series of Syllabus Bites related to direct and indirect proportion. Students use graphs, equations and numerical methods to solve problems involving direct proportion.

Moving Image

Nautical Robots

How might you find out how much and where the Earth's oceans are warming? Watch the report by Ruben Meerman and discover how more than 3000 'nautical robots', known as argo floats, have been placed in the oceans to collect data on variations in temperature, pressure and salinity.

Teacher resource

TIMES Module 35: Number and Algebra: proportion - teacher guide

This is a 22-page guide for teachers. The module introduces the idea of direct proportion and illustrates its many uses in science, commerce and measurement. It looks at ratios, gradients and fractions. A history of the development and use of proportion concludes the module.

Interactive Resource

Sites2See – applied mathematics

This collection of resources for Applied Mathematics has helpful links for the six Focus Studies - Communication, Driving, Design, Household Finance, Human Body and Personal Resource Usage. A laptop-friendly resource.

Assessment resource

Vitality drinks: assessment

Assess your ability to make drinks from a menu to match customer orders. For example, calculate the volume of each juice type required when given the ratio of juices for a drink of a particular total volume. Watch an animation to determine the ratio of juices in a new recipe. Calculate the volume of each juice in the new ...

Interactive resource

EagleCat: linear graph

Explore the graphs of linear equations in the form y = mx + c. Observe changes to the gradient and y-intercept under various transformations. Alternately, change the equation and observe changes in the y-intercept or change the y-intercept and see how the equation changes.

Interactive Resource

Solution of simple linear equations

This is a six-page HTML resource about solving problems concerning simple linear equations. It contains five questions, three of which are interactive, and one video. The resource discusses and explains the solution of simple linear equations to reinforce the students' understanding.

Teacher resource

reSolve: Real World Algebra: Linear Functions

This sequence of two lessons explores real world, algebraic, numeric and graphical representations of linear functions, focussing on the gradient of linear functions. Students use images of everyday objects and inscribe straight lines, then use Geogebra to explore the algebraic representation of their lines. Each lesson ...

Interactive Resource

Linear equations and inequalities

This resource is a collection of screen displays of questions relating to linear equations and inequations. Graphing tasks involve determining the coordinates of two points on the linear function. Other tasks are presented as multiple-choice questions and involve finding slopes of lines, calculating intercepts with the ...

Interactive Resource

Substitute values into simple linear equations

This is a five-page HTML resource about solving problems concerning substitution into simple linear equations. It contains four questions, one of which is interactive, and one video. The resource discusses and explains substitution into simple linear equations to reinforce students' understanding.

Video

Introduction to slope

In this animated presentation students are introduced to the mathematical concept of slope (or gradient) of a straight line. The mathematical definition of slope is explained in terms of, and derived from, two practical contexts.

Moving Image

Solving equations with the distributive property

This is a video demonstration of solving a linear equation by algebraic means. In the commentary, the presenter carefully explains the step-by-step method used to solve this example, which includes use of the distributive law and collecting like terms to simplify the equation. Having found the solution, the presenter verifies ...

Teacher resource

Coordinate geometry

This is a website designed for both teachers and students that addresses coordinate geometry from the Australian Curriculum for year 9 students. It contains material that shows the connection between algebra and geometry through graphs of lines and curves. There are pages for both teachers and students. The student pages ...

Interactive resource

Graphing: line of best fit

Plot some data points on a graph. Estimate the position for a line of best fit. Use a graphing tool to check your estimate. Add more points to see how they affect the position of the line of best fit.