Stanford University offers this unique online course designed to help students of all ages and levels (and their instructors) develop "strategies to learn and to relate to math well." Taught by Dr. Jo Boaler, a professor of mathematics education at Stanford, this course is intended to help students who have had negative experiences with math classes gain both the confidence and the metacognitive...

From Marco Santonocito and Antonio Giarrusso, iMathematics is a free phone application for practicing a variety of mathematical subjects, including arithmetic, algebra, geometry, trigonometry, calculus, and probability. As Giarrusso explains, this phone application can be considered "the Duolingo for Learning Math." Like the popular application for learning new languages, iMathematics teaches...