This site really keeps it simple. It allows students to set a timer and test their knowledge of basic math facts after listening to audio prompts that are very clear. After the game ends, they can check their answers and they are prompted to practice the facts they missed and take the quiz again. That's A Fact has a clear interface, amazing sound, feedback, and an assessment. I believe this simple site will engage students to practice math facts when they may not be so willing to on a paper/pencil worksheet.
The audio supports English Language Learners (of all ages) and your special education students. A timer is optional and the quiz/game has 30 facts.
This would be a good site to use with an Interactive White Board. Students would touch the numbers at the bottom of the screen to answer the questions. I think it would be easier than using a mouse.