Coordinate City Racer: Plotting Points on the Grid
Every point on the grid has an address: crawl across first, then climb up, and you will always land in the same spot.
Giving a point an address
Imagine a city map with numbered avenues running across and numbered streets running up. To describe exactly one spot in the city, you need two numbers — which avenue, and which street. A grid works the very same way. Every point has its own address made of two numbers, called an ordered pair.
Plotting step by step
To plot the point (4, 3): start at the origin. Crawl 4 units to the right along the x-axis. From there, climb 3 units straight up, parallel to the y-axis. Mark that spot — that is the point (4, 3).
Reading a point's address
You can also work backward: given a point already plotted on the grid, count how many units it sits to the right of the origin (that is its x-coordinate), then count how many units it sits above the origin (that is its y-coordinate). Together, those two numbers are its ordered pair.
- Start at the origin, (0, 0).
- Crawl 4 units right along the x-axis.
- From there, climb 2 units up.
- Mark the point where you land.
- The x-coordinate is how far right: 5.
- The y-coordinate is how far up: 3.
Check your understanding
- The coordinate plane locates points using two perpendicular number lines: the x-axis (horizontal) and y-axis (vertical), meeting at the origin (0, 0).
- An ordered pair (x, y) gives a point's address: x tells how far to crawl right, y tells how far to climb up.
- Always plot the x-coordinate first (across), then the y-coordinate (up).
- Order matters — (2, 5) and (5, 2) are different points, which is why it is called an ordered pair.
- You can read a point's coordinates by counting how far right and how far up it sits from the origin.