You will probably need paper and pencil for most of these sites
Decimals From Learning Wave – word problems involving decimals
http://www.learningwave.com/lwonline/workingfront/decimalsfront.html
Multiplication of Decimals Jeopardy
http://www.quia.com/cb/95593.html
Multiplication and Division Decimal Jeopardy
http://www.quia.com/cb/147595.html
Draggable Decimals
http://mrnussbaum.com/decimals-workshop/
FunBrain – Power Football
http://www.funbrain.com/football/index.html
Decimals Cruncher – Multiplication
http://www.coolmath-games.com/decimals-cruncher/decimals-cruncher-multiplication.htm
Decimals Cruncher – Division
http://www.coolmath-games.com/decimals-cruncher/decimals-cruncher-division.htm