Start from zero — the basic math you need before everything else
A point's address is written as a pair (x, y). The first number tells you how far to go left or right along the x-axis. The second tells you how far up or down along the y-axis. The order matters: (3, 2) is not the same point as (2, 3).
To plot a point, always go across first, then up or down, like reading a map reference. Negative numbers mean the other direction: negative x is left, negative y is down. To read a marked point, count across to find x, then up or down to find y.
Plotting is like reading a treasure map: '3 paces east, 2 paces north' lands you on one exact spot. The first number is always the across step, the second the up step. Swap them and you dig in the wrong place — (3, 2) and (2, 3) mark different X's.
▶ Plotting Points