We use Xtramath.org in our classroom. It is a free, web-based math fact fluency program that helps students memorize addition and subtraction facts. Please contact me if you can't remember your child's login information.
Stop the Clock
Grade level addition, subtraction, geometry, and logic games.
Enter a parent email address to track progress.
Addition, subtraction, multiplication, and division games to build fluency
Games and practice quizzes organized by grade
Various skills organized by grade
This is not a game, but an excellent website that allows you to create your own worksheets based on grade level topics.