This site brings you all of the most useful rules of Algebra in one place in an easy to understand format with examples for free!
Algebra Rules
PhotoMath
The application reads and solves mathematical expressions by using the camera of your mobile device in real time.
Math Drills
This site offers a collection of math worksheets for a variety of different kinds of math for free!
Underground Mathematics
This site offers free resources for teaching math that enables students to explore the underpinning connections of mathematics.