Coordinates in the first quadrant — introduction

Coordinates in the first quadrant — introduction

Coordinates in the first quadrant

Imagine you've drawn a treasure map on squared paper. You want to tell a friend exactly where the treasure is buried — not "somewhere over there", but the exact square. The trick is to use coordinates: a pair of numbers that pin one point onto the grid.

In Year 4 we learn to read and plot coordinates in the first quadrant — the corner of the grid where both numbers are positive (we'll meet the other corners in a later year).

The two number lines

A coordinate grid is made from two number lines that meet at a corner.

  • The horizontal line is called the x-axis. It counts how far you go to the right.
  • The vertical line is called the y-axis. It counts how far you go up.
  • The point where the two lines meet is the origin, with coordinates (0, 0).

Both axes are labelled 0, 1, 2, 3, 4, … going outward from the origin. The squares between gridlines are all the same size.

What a coordinate is

A coordinate is a pair of numbers in brackets, separated by a comma:

(3, 5)

The first number is the x-coordinate — how far across (right of the origin).

The second number is the y-coordinate — how far up.

So (3, 5) means: from the origin, go 3 squares right and then 5 squares up. That spot is the point (3, 5).

⚠️ The order matters. (3, 5) is not the same as (5, 3). The two points sit in different places. Always x first, y second — "along the corridor, then up the stairs".

A worked example

Where is the point (4, 2)?

  • Start at the origin (0, 0).
  • Move 4 squares to the right along the x-axis. You're at (4, 0).
  • Move 2 squares up. You're at (4, 2).

Where is the point (2, 4)?

Different point.

  • Start at the origin.
  • 2 squares right. You're at (2, 0).
  • 4 squares up. You're at (2, 4).

(4, 2) and (2, 4) sit in clearly different spots. That's why the order is important.

The "first quadrant"

The two axes split the page into four corners called quadrants. The first quadrant is the one where both x and y are positive — the upper right corner.

In Year 4 every coordinate has both numbers ≥ 0, so all our points sit in the first quadrant (or on the axes, where one of the numbers is 0).

Negative coordinates and the other quadrants come later — for now, all the action happens in this single corner.

What you will learn