I use this as an intro to the constant velocity unit in physical science or physics. I have students predict trends prior to collecting data and graphing. I also have students use Desmos to get the linear trend after making their own graphs and best fit lines. I find that using "for every" statements with slopes help students understand that slopes aren't just a number and slopes should have units. For example, "for every one marker added to the cup, the mass increases by...." or "for every 1 cm increase in length, the mass increases by..." or vice versa.