A Chemical Jigsaw Puzzle - Collection of printable learning aids to help improve the understanding of combining powers (valences) in chemical reactions. - http://www.harmsy.freeuk.com/jigsaw.html
Balancing Chemical Equations Tutorial - Visual shockwave exercise in which you type in coefficients and check your answers. - http://www.mpcfaculty.net/mark_bishop/balancing_equations_tutorial.htm
Balancing Chemical Equations - Shockwave activity to help in balancing equations. - http://www.mcli.dist.maricopa.edu/proj/mu/eqbal/