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