Rise ( vertical line) over Run ( horizontal line.).....just count blocks from one pair to the other , it forms a triangle.. in your case you count 4 to the right on the x axis and up 4 on the y axis and you get...4/4=1 you read the slope ( line) of the paired numbers from left to right ..if line is going up....it is positive...if it is going down, it is negative. just do a few and it will become easy...