This document discusses slope and how to calculate it. It defines slope as the ratio of the rise over the run between two points on a line. A vertical line has an undefined slope since the run is zero. For a non-vertical line, the slope is calculated as the change in y-values divided by the change in x-values between two points. The slope indicates whether the line rises or falls from left to right. An example demonstrates how to sketch a line given its slope and a point.