Here is the description of their site in their own words:
It is our dream that teachers won’t have to hunt and search for activities for hours or spend a fortune on materials. We hope to continue to build this site until it is a comprehensive collection of teaching materials across several grades. The site currently focuses on kindergarten-third grade objectives. We have begun with mathematics but will continue to create across subjects. Our next focus will be science and social studies because it is so difficult to find quality, free materials for those areas.
The games are divided into the following math strands: Number & Operations, Measurements, Geometry, Data & Probability, Algebra, and Problem Solving.
They have many games already on the site but here are a few of my favorites:
Help Andy Ant get to the picnic. Andy has been walking from ant hill to ant hill trying to find a picnic. Help Andy choose the best path to get to the picnic in the correct amount of inches.
In addition to the great math games there are also several interactives on the site such as:
Base 10 Block Manipulatives, Number Line, and Venn Diagram.
All of Fuel the Brain's activities work great on the Smart Board but would also be fabulous for a student to use individually. You definitely want to check this website out!