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.