Dictionary: http://www.dictionary.com
Spelling: http://www.spellingcity.com
Web Searches: http://www.nettrekker.com
Math Games:
Thinking Blocks: http://www.thinkingblocks.com/thinkingblocks_ratios/TB_Ratio_main.html
Fractions, Decimals, Percents: http://www.mathplayground.com/Decention/Decention.html
Mixed Review: http://www.mrnussbaum.com/compcastle.htm
South America: http://www.sheppardsoftware.com/South_America_Geography.htm