Straight Line Graphs | Year 9 Maths PowerPoint Lesson

This lesson covers the form y = mx + c: what the gradient and y-intercept control, how to plot a line from a table of values, and how to calculate a gradient from two coordinates with the correct sign. Pupils also rearrange equations into y = mx + c, recognise horizontal, vertical and diagonal special cases, test whether two lines are parallel, and interpret m and c in a real charging context. Three gradient traps that cost marks every year are addressed directly. It is a ready-to-teach PowerPoint scaffold for an hour-long lesson on straight line graphs, with four worked examples, a plotting task and six mixed questions.