# Day 5: The Dreaded ZigZag

*College-Prep* *Physics*: In two of the CP classes, students graphed their ball bounce data. Part of it was for me to see were they are with their graphing skills and help correct mistakes. The classroom arrangement isn’t very conducive to walking around and looking at their work, so I was just talking from the front of the room as questions arose. It wasn’t a great lesson, and I need to revise it for my third CP class on Monday.

I tried using the above visual to show why “zigzag” breaks on graph axis can be bad. The paper folds over to show how the zigzag part is eliminated and creates a false y-intercept. (Thinking about this now, it would be even better if the graph was a parabola or square root. You couldn’t tell if the trend curved or not if the beginning of the graph was zigzagged out.)