(Sample link) NASA for middle-school students http://www.nasa.gov/audience/forstudents/5-8/features/index.html
(Sample link) National Geographic for Kids http://www.nationalgeographic.com/kids/
This link is to the State of Tennessee's website. These practice questions are the same as the purple workbooks that the county has provided for us to use in our classrooms. It is a great source to use while preparing for the TCAP Test. This is the entire workbook, but math is found on pages 53-96. When you get to the Tennessee website, scroll down and click on Grade 6. http://state.tn.us/education/assessment/ach_samplers.shtml