TI Math is my go to place to find higher thinking activities as well as practice
The activities on the TI Math site are so encompassing that I can use it for virtually anything I want. One drawback is the search tool. It is not very user friendly until you become really familiar with how to search. I like the fact that I can send different levels of the same material to my students depending on their level of ability.
How I Use It
I use TI Math several times a week in my classroom. I love the activities and the fact that they have activities for every possible topic and every possible level. A large amount of the activities are created by TI but users can also submit activities for publication. Most activities do the "crunching" of numbers for students and allows them to explore the math behind it. It raises their depth of knowledge by letting them learn the behavior of math instead of getting bogged down in computations. However, if you are introducing a topic, there are excellent activities that take students step by step through a process and show them how to do it. This website can be used for instruction, remediation or acceleration depending on your students needs.