Rise over run... rise over run... rise over run....

Every year, slope is such a difficult concept for students, given that it seems such a simple one in reality, and one so easily applicable to real life. Stairs, roof lines, even road grades are measured in slopes. Counting how far up, compared to how far over, seems trivially(is that a word??) easy.

We talk about rate of change, in particular how things change over time, comparatively. We look at graphs of points, lines, and explore many different scenarios. I even developed a game called Slope Mania for them to practice slope. Still, for so many students, it seems like black magic!

What is so difficult??? How can I make this concept easier for them to understand???