Every New Zealand maths department has watched a graphing lesson turn into a logins lesson. Devices arrive, twenty minutes evaporate on passwords and file sharing, and the class ends up graphing three lines they could have drawn by hand in a quarter of the time. Linear functions is genuinely a topic where digital tools earn their place at curriculum level 5, but only for a narrow set of jobs. This is about which jobs those are.
The question a digital task has to answer
Before you open anything, ask whether the tool lets students ask a question they could not ask on paper. If not, it is decoration. Drawing y = 2x + 3 on a screen is no better than drawing it in a book. Dragging a slider through fifty values of the gradient in eight seconds and watching the line pivot is something paper cannot do at all. That distinction kills about two thirds of the digital activities floating around, and it protects your planning time as well.
Sliders, and the three things they show
Graphing software with a live parameter is the strongest digital move available on this topic. Set up y = mx + c with sliders on both and give students exactly three instructions: make the line steeper, make it go downhill, move it up without changing its steepness. Nothing else. Ten minutes.
Those three tasks isolate gradient magnitude, gradient sign and intercept as independent ideas, which students routinely conflate. The conversation afterwards is where the learning is fixed, so budget more time for talk than for screens. Structured discussion prompts help here, and the Linear Functions – Teaching Kit with Puzzle, Talk Cards & Practice carries talk cards that give you the questions to put up once the devices are shut, which is usually the harder half of planning.
One shared spreadsheet, one class data set
The second job worth doing digitally is collective data. Have each student measure something linear, the height of a stack of cups against the number of cups is the reliable one, and enter their result in a shared sheet. Thirty rows appear in four minutes. Then plot the lot.
What this buys you is scatter. Real measurements do not sit perfectly on a line, so students meet the line of best fit as an obvious response to a problem in front of them rather than as a definition. A measurement taken in the school grounds also holds attention better than a textbook example about taxi fares. Set the sheet up yourself, locked except for one column; letting thirty students design a spreadsheet is a different lesson.
Slides that do exactly one job
The most useful slide deck for this topic is not a lesson in slides. It is a single slide, on the screen for the whole hour, showing the four graphs students must be able to sketch from memory by the end. Change it once at the halfway point. Everything else goes on the board where you can write on it.
Where you do want a fuller deck, make it editable so you can strip out what your class does not need. Sequenced workbook material pairs well with that approach, and Algebra – Linear Functions and Systems of Equations | Foundations & Problem Solving Workbook | GRADE 7–10 gives you the printable practice that should follow a screen activity, so the digital part stays as the exploration and the consolidation happens in a book.
What stays on paper, and why
Sketching a line from an equation should stay handwritten for the whole unit, as should rearranging into gradient-intercept form. Both are skills NCEA Level 1 assessment will ask for where no device is available, and both degrade when students always have autocomplete. Use the screen to build understanding and the page to build fluency. Equity matters here too: where some students have a device at home and some do not, any task requiring one outside school hours widens a gap you spend the year closing. Keep digital work inside lesson time and set homework on paper.
Where the topic goes next
Students who have played with sliders arrive at transformations already expecting a parameter to do something visible, which makes the senior work considerably faster. When your Year 11 and 12 classes reach that stage, Algebra – Higher-Level Functions and Graph Transformations | Foundations for Pre-Calculus Workbook | GRADE 9–12 extends the same reasoning to quadratics and beyond. Run it this way and the lesson you get is one where the devices are closed by the thirty-minute mark and the argument about what happens when the gradient is negative is still going.
Comments
No comments yet — be the first to share your thoughts!
Leave a comment
Comments are reviewed before being published.
Thanks for your comment!
Your comment is being reviewed and will appear here shortly.