Varsity Tutors
Varsity Tutors: Hotmath: Slope of a Line
Twenty-two problems present a practice finding the slope of a line. The solutions are only available with a paid subscription.
ClassFlow
Class Flow: Slope
[Free Registration/Login Required] This lesson provides class experiences with whole group instruction on understanding slope.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: When Is a Slope 0 or Undefined?
At this site Dr. Math gives a discussion on the slopes of lines. The Dr. gives an analogy between the slope of a line and walking up and down hills. The Dr. explores the concept of undefined and zero slopes through his response to a...