The Number Plane

The number plane, or Cartesian plane, uses an \(x\)-axis and a \(y\)-axis to give every point a pair of coordinates such as \((-3, 2)\). In NSW Year 8 maths, students extend this to coordinates that are decimals or fractions (NESA outcome MA4‑LIN‑C‑01).

You will plot and read points in all four quadrants and on the axes, name the quadrant from the signs alone, and place a point from its distances to the two axes. You will then use coordinates to find horizontal and vertical lengths, the areas of a trapezium and a kite, and the length of a bushwalk drawn on a grid, which needs Pythagoras' theorem. These skills set up every graph in this topic. It is part of Year 8 Graphing Linear Equations.