Massachusetts Institute of Technology
Mit: The Wind Swe Home Page
This is a technical site from MIT. It provides data and information from satellites which observe solar winds. Provide 3-D models of the heliosphere and uptodate plots of solar wind data.
Khan Academy
Khan Academy: Add and Subtract Fractions: Word Problems
In this exercise, students practice adding and subtracting fractions with unlike denominators word problems. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.