Khan Academy offers instructional videos to help students in math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, English, and more.

Purple Math has a large number of "how-to" videos that explain math concepts from Pre-Algebra, Algebra 1, Gometry and Algebra 2.

Virtual Nerd has over 1,500 video lessons covering Pre-Algebra, Algebra 1, Algebra 2, and Geometry.

Patrick Math offers free online videos covering basic math, Algebra 1, Algebra 2, Trigonometry, Calculus, and Probability and Statistics.

Learn to Be helps students from underserved communities unlock their potential by connecting them with exceptional tutors online, for free.  A parent/guardian can enroll their student in this tutoring program to get one-on-one support.