Coordinates

Coordinates give a position on a grid: (x, y) means go across x, then up or down y. The x-axis goes across and the y-axis goes up. Negative numbers go left or down.

Key facts

  • Along the corridor, then up the stairs: x first, then y.
  • The origin is (0, 0).
  • Midpoint: add the x’s and halve, add the y’s and halve.

Worked examples

Example 1

Find the midpoint of (−4, 1) and (2, 5).

  1. x: add and halve. (−4 + 2) ÷ 2 = −1
  2. y: add and halve. (1 + 5) ÷ 2 = 3
  3. So (−1, 3)

Answer: (−1, 3)