How do you classify the slope of a line ?

Y=mx+b 

slope= rise
          run
If its already graphed then you find where the line meets the y- line ( thats the b in the equation) from there you go up or down on the y- line to the point where the line next meets directly over another vertical line on the grid, the number of times you moved up or down is the "rise" in the equation for slope. After finding rise your move left or right from that point on the y-line until you meet the point where the line is and that will be the run. That fraction or number once you simplify the equation is you slope. Hope that helps.