Designed and maintained by Elizabeth Stapel, an educator and holder of an advanced degree in mathematics, Purplemath contains hundreds of lessons designed to help students who might be having trouble with algebra. As Stapel notes on the site’s homepage, “These lessons emphasize the practicalities rather than the technicalities, demonstrating dependable techniques, warning of likely “trick” questions, and pointing out common mistakes.” Visitors can get started by clicking on the “Lessons Index” tab on the left-hand side of the homepage, and they will be whisked away to a categorized section that contains lessons on dozens of algebraic situations, such as using the midpoint formula, finding the slope of a straight line, and graphing systems of linear inequalities. The site also contains a section of external sites which have been reviewed by Stapel, including those that offer quizzes, worksheets, and related materials.