Mathematics / Year 9 / Number and Algebra / Linear and non-linear relationships

Curriculum content descriptions

Find the midpoint and gradient of a line segment (interval) on the Cartesian plane using a range of strategies, including graphing software (ACMNA294)

Elaborations
  • investigating graphical and algebraic techniques for finding midpoint and gradient
  • recognising that the gradient of a line is the same as the gradient of any line segment on that line
General capabilities
  • Numeracy Numeracy
  • ICT capability Information and Communication Technology (ICT) capability
ScOT terms

Cartesian coordinates,  Gradients,  Midpoints

Online

reSolve: Gradient and Tangent

This sequence of two lessons investigates gradient and angle by applying the tangent ratio to find the angles represented by a road sign or the angle of a street. In the first lesson, students research what a road grade is and determine the actual angle of a road given its grade. They then construct their own road sign ...

Online

Secondary mathematics: different representations

These seven learning activities, which focus on 'representations' using a variety of tools (software) and devices (hardware), illustrate the ways in which content, pedagogy and technology can be successfully and effectively integrated in order to promote learning. In the activities, teachers use different representations ...

Interactive

Laptop wrap: Parallelendicular

Students construct a series of GeoGebra applets that investigate the parameters gradient and intercepts of straight lines. They reinforce this knowledge with Microsoft Math 3.0. 

Interactive

Laptop wrap – a slippery slope

Distance, midpoint and gradient are investigated as students design an Excel spreadsheet and make a Smart Notebook presentation on ski-lifts. Students then contribute to a discussion on the steepest street in the world. 

Online

Graphs: Year 9 – planning tool

This planning resource for Year 9 is for the topic of Graphs. Students work with points, straight lines and line segments on the Cartesian plane, and use the coordinates of points to apply the formulas for calculating the gradient, midpoint and length of a line segment (distance between two points). They use digital tools ...

Video

MathXplosion, Ep 33: On the grid

Explore graphs, grids and mapping with a focus on reading and writing location data using coordinate geometry. Grids and maps illustrate the concepts of parallel/perpendicular lines (axes or labelled number lines), ordered pairs and intersection points.

Online

reSolve: Rectilinear Polygons

In this sequence of three lessons, students use geometric reasoning to establish relationships between angles in polygons and go on to make generalisations using algebraic expressions. Students explore and enumerate right angles in a series of rectilinear polygons and generalise their findings. They then explore the number ...

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 ...

Interactive

The Numberline

An interactive tool that can help students explore a number line, including points representing integers, fractions and decimals

Online

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.

Online

TIMES Module 29: Number and Algebra: introduction to coordinate geometry - teacher guide

This is a 22-page guide for teachers. This module introduces coordinate geometry. The introduction includes finding the distance between two points, finding the coordinates of the midpoint between two points, determining the gradient of a line and determining the equation of a line.

Online

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 ...

Online

Mathematical modelling (Algebra): Year 9 – planning tool

This planning resource for Year 9 is for the topic of Mathematical modelling. Students use algebraic rules, tables, graphs and digital tools to construct linear and quadratic models for a range of real-life situations, make predictions and solve related problems. They spend time identifying variables to formulate the models ...

Online

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

Desmos Graphing Calculator - Google Play app

Plot functions, create tables, add sliders and animate your graphs. Touch points of interest on the graph to show maximums, minimums and points of intersection. Type in an equation and watch the calculator solve the problem. Free when reviewed on 12/5/2015.