Eleven years ago, I wrote a post titled What is All the Fuss About Lines? In it, I discussed the difficulties that students encounter when asked to determine the equation of a line. Faced with formulas for calculating slope, the point-slope form of a line, and the slope-intercept form, students lose their common sense as they become mired in the algebra.
As something of an antidote to these difficulties, the websketch below (and here) presents four engaging games all relating to slope. These games do not ask students to compute slopes, nor do they provide the coordinates of any points. Instead, they develop students’ ability to eyeball the slopes of given lines or to adjust lines to match given slopes. Without any of the burdens of algebra or computation, these games can help provide students with some basic intuition about the nature of slope.