Put the Point on the Line

The goal of this activity is to sharpen students’ focus on slope. As students place points on an imaginary line, the activity asks them to estimate first, then calculate, and then notice proportionality. Use student ideas here to define slope as a ratio of change in `y`-coordinates to change in `x`-coordinates. By the time students get to the end of the activity, they should have a number of ways of talking about this, but it’s unlikely they’ll write a fraction with `∆y` in the numerator and `∆x` in the denominator. They’ll be ready for you to introduce this idea. French translation courtesy of Maryse LeBouthillier: https://teacher.desmos.com/activitybuilder/custom/58ebdaab6f8f4e0c724c9167

By Desmos _