Freerice.com is a free website that is educational and helps students give back. Each time you answer a multiple choice vocabulary question right you generate enough money for the United Nations World Food Programme to buy 10 grains of rice to help reach Zero Hunger.

Classic game, quick and fun.

The Washington Post daily Sudoku puzzle.

Another one from the Washington Post. Kind of like Boggle!

Multiplying

Addition/Multiplication Game

Multiplying

*FLASH NEEDED!* This site makes the idea of blood typing (and how different blood types interact with each other) crystal clear. The game, housed at NobelPrize.org, places you in an emergency room. There’s been a car crash, and patients need a blood transfusion. It walks you through drawing blood, deciding what type it is, and completing the transfusion, making science connections all the way.