Math Medics
S.o.s. Math: The Geometric Series
The process of adding infinitely many numbers is at the heart of the mathematical concept of a numerical series. This lesson gives a tutorial on geometric series. Includes sample problems and solutions.
Wolfram Research
Wolfram Math World: Series
This page gives a great overview of series in mathematics, including a definition of convergence and divergence. Provides links to more information about specific types of series.
Math Aids
Math Aids: Patterns Worksheets
Great resource for learning and practicing working with patterns. Math worksheets are printable, may be customized, and include answer keys.