Coordinates (age 11+)
Plot and read coordinates in all four quadrants of the Cartesian plane, using positive and negative x- and y-values to describe positions precisely
What a learner can do afterwards
- Plot points with negative coordinates accurately in all four quadrants
- Identify the quadrant a point belongs to from its coordinate signs
- Read coordinates from a graph including fractional and negative values
1 · Read
You already know how to plot points using an x-axis and a y-axis. Those two lines cross at a point called the origin, (0, 0), and split the plane into four regions called quadrants.
The four quadrants follow a pattern based on the signs of x and y. Quadrant I is (+, +), top right. Quadrant II is (-, +), top left. Quadrant III is (-, -), bottom left. Quadrant IV is (+, -), bottom right. Letters follow the same rules. If n is positive, -n is negative. So with n = 5, -n is -5, left of zero. A point with a minus in front of a positive letter follows the number rules above.
To plot (-5, 3): start at the origin, move 5 steps left because x is negative, then move 3 steps up because y is positive. You land in Quadrant II.
Numbers do not have to be whole. A point like (-1.5, 2.5) sits halfway between the marked lines, still following the same left-right, up-down rules.
A point's quadrant is decided by the signs of its coordinates: read x first for left-right, then y for up-down.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
19 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.