Algebra

http://www.vectorkids.com/vkvariable.htm


http://www.aaamath.com/g723-evaluate-1variable.html


http://www.aaastudy.com/ad24.htm


http://www.math-play.com/soccer-math-one-step-equations-game/one-step-equations-game.html

 http://www.mangahigh.com/en/games/algebrameltdown