A coordinate pair tells you where a point sits on a grid. It is written as (across, up) — the first number is how far to move right along the x-axis, and the second is how far up the y-axis. Always start at the origin, the corner where the axes cross, which counts as 0, not 1. Then count the spaces you move, not the lines you pass. So (3, 2) means 3 across and 2 up. Going up before across, or counting the first line as 1, lands the point in the wrong place.
Explore this idea with maths tools
Maths you can move
Build 8 + 5
Tap two gold counters to fill the ten-frame.
8 in the frame + 5 waiting. The total stays the same.
Words to know
- origin
- the point (0, 0) where the axes cross
- x-axis
- the across (horizontal) number line
- y-axis
- the up (vertical) number line
Worked examples
Plot 3 right and 2 up from the origin.
- 1.Start at (0, 0).
- 2.Across 3, then up 2.
= (3, 2)
Plot 1 right and 4 up from the origin.
- 1.Start at (0, 0).
- 2.Across 1, then up 4.
= (1, 4)
Plot 5 right and 2 up from the origin.
- 1.Start at (0, 0).
- 2.Across 5, then up 2.
= (5, 2)
For parents
Method: 'Along the corridor, then up the stairs.'
What to say: Say 'x comes before y, so across comes before up', and start counting at 0.
Common mistakes:
- Swapping the numbers, going up before across.
- Counting the first gridline as 1 instead of starting at 0.