The following is a list of full math courses, online and free:
FlippedMath: Videos and worksheets for Algebra 1 and 2, Geometry, Pre-Calculus and AP Calculus
MasterMath: Algebra 1 videos and worksheets. (Also has middle school math resources).
SchoolYourself: Video lessons cover algebra, geometry, trigonometry, precalculus and calculus.
Algebra 1: SAS Curriculum Pathways
Beginning Algebra: Saylor Academy.
Algebra and Geometry: Hippocampus
Algebra 1, 2, Geometry: Math Planet
Calculus 1: Ximera
Georgia Virtual Learning: This site has a number of online high school math courses that can be accessed for free.
Algebra 1: This is a full course, broken into modules, so you can use it in its entirety, or just the parts you want. The course includes lesson plans, with links to related Khan Academy videos, worksheets and assessments with their answer keys, and each unit ends with a real-world project.
Geometry: The course is modular, so it can be used to supplement an existing Geometry program, or serve as the main curriculum. It's project-based, emphasizing real-world examples, such as using Geometry to create architectural designs for an apartment or house, or designing a floor plan that maximizes open space and natural light.
Calculus: Covers Limits & Continuity, Derivatives, Applications of Derivatives, Integrals, and Applications of Integrals. Includes links to workbooks and videos.
Math Video Library: Visit Mathispower4u.com for video tutorials in Algebra 1 and 2, Geometry, Trigonometry, and Calculus.
For additional free math textbooks for multiple grades, click here.