My classes seriously struggle every year with what slope means. They never seem to grasp that a slope that goes down and left is still positive. This Google sheet forces them to think about what slope really means and type it. Students will fill in 2 columns for slope. One for when they go up and one for when they go down. Then, they will find the equation of the line. I have my students blank graph paper and had them also make the graphs of these lines. After 12 problems of solving and graphing, I will say that it was much better. I hope your class has the same luck!