Resources that I have found useful in my math efforts.

The Integral Calculator is an impressive online tool for free use. Encouraging all students to thoughtfully learn and apply math, this tool is nevertheless excellent for checking work. Further it has proven useful in sometimes spotting errors in math texts I use.

Khan Academy is another excellent resource! An entire landscape of math areas are provided. Each has excellent video presentation, along with regular quizzes and the like. Its a free site and it is used in public schools. Energy points are provided for getting the correct answers, providing visual affirmation you are making progress! Its a fun website!