you need to see how high up and how far across it takes to get to the next dot.
if starting at (2,1) I gotta go up 1 and to the right 2
slope is vertical count/horizontal count
1/2
you can also solve algebraically but it gets complicated since you need to use 2 points and subtract
y2-y1/x2-x1 (2-1)/4-2) = 1/2
