Cross two number lines and you get a map for points. Learn to plot a point from its coordinates, and to read off the coordinates of a point you see.
A coordinate plane is made of two number lines that cross. The horizontal one is the x-axis, the vertical one is the y-axis, and the point where they meet is the origin — that's (0, 0).
Every point has an address called an ordered pair, written (x, y). The order matters: the first number is x (how far over — right or left), the second is y (how far up or down).
x comes before y, just like in the alphabet. Say it as "over, then up." Mixing them up sends you to a totally different spot: (3, 2) and (2, 3) are not the same point!
The two axes split the plane into four regions called quadrants, numbered with Roman numerals counter-clockwise starting from the top right. Each quadrant has its own pattern of + and − signs.
Switch between the two skills: plot a point from its coordinates, or name the coordinates of a point you're shown.
Plot each point in order and watch the lines connect. Can you tell what the mystery picture will be? There are several hidden pictures — tap New Picture for a different one.
A mix of plotting and naming. For plot problems, tap the grid at the right spot. For name problems, set the coordinates of the shown point. You earn a point for each one correct on the first try.