Desmos
Desmos is a free graphing and teaching tool for math available on the web as well as on iOS and Android. In addition to plotting equations, classroom activities are available to help students learn about a variety of math concepts.
GeoGebra
GeoGebra is an interactive geometry, algebra, statistics and calculus application, intended for learning and teaching mathematics and science from primary school to university level. It is available on multiple platforms, with apps for desktops (Windows, macOS and Linux), tablets (Android, iPad and Windows) and web.
Khan Academy
This resource contains video explanations, examples, and practice problems with answers for Arithmetic, Algebra (all levels), Geometry, Statistics, Calculus 1, 2, and 3, Differential Equations, Linear Algebra, plus more math topics and other subjects.
Hippo Campus
Video presentations, examples, simulations, and test preparation for various math and non-math subjects including Arithmetic, Algebra, Geometry, Calculus, Differential Equations, Linear Algebra, Statistics & Probability, Physics, Biology, History, and Psychology.
Purple Math
This is a great resource for basic math; beginning, intermediate, and advanced (college) algebra; word problems. Watch video explanations, do practice problems, learn immediately whether the answers were correct or not. Worksheets and preparation for standardized tests are also available.
Paul’s Online
Provided by Lamar University, this web site is helpful for students wanting information on college algebra and all levels of calculus. View class notes and explanations, downloadable handouts, practice problems, and reviews.
West Texas
The West Texas A & M University web site offers assistance in the beginning, intermediate, and advanced (college) algebra. View tutorials, work sample problems, or prepare for the GED.