Further Learning

If you want to find out more about a topic, feel free to browse the following websites.

Graphing

Coordinate System - http://en.wikipedia.org/wiki/Coordinate_system
Cartesian Coordinate System (this is what you use!) - http://en.wikipedia.org/wiki/Cartesian_coordinate_system
Sets and Lines - http://www.wtamu.edu/academic/anns/mps/math/mathlab/beg_algebra/beg_alg_tut2_sets.htm

Numbers, Data, Functions, Oh My!

Discrete vs. Continuous - http://www.themathpage.com/areal/continuous.htm
Real Numbers - http://en.wikipedia.org/wiki/Real_number
All of the Symbols of Number Sets - http://www.mathsisfun.com/sets/number-types.html