If you have never used http://web.archive.org/web/20160910185152/https://www.khanacademy.org/in your classroom, it might be a good time to do so. If it has been a while since you have been there, it might be a good time to go back. Khan Academy is a wonderful resource that is constantly expanding to offer more and more help to children in a variety of subjects. While it started as simple tutorial math videos, it has evolved into a dynamic and interactive instructional support platform. They ways that the resource could be used are various and exciting. Potentially, it could be used to enhance and extend the learning for students beyond the walls of the classroom. They describe what they offer in this way.
"Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content."
Perhaps most remarkable of all, it is free to use.