The "Big Questions" page on this NASA site is only one of its many resources students could use. This site covers current science news, astronomy information, and more.
Teachers can see a collection of tens of thousands of resources by grade levels.
PreK K-2 3-5 6-8 9-12 13+
You can click on a collection of tens of thousands of resources by subject area.
They also have a blog teachers can follow for tips on curriculum.
Science
Mathematics
English Language Arts and Literacy
The Arts
Health and Physical Education
Preschool
Social Studies
World Languages
This site is wonderful for English, Math and Science. It has videos on on kinds of topics that include games you can play. I like how it allows students to research at an early age. It is user friendly and easy to use. You can play games, watch videos, read or take a quiz on different subjects.
Free elementary, middle and high school teacher resources, including puzzlemaker, student games and activities and lesson plans. I like how they have engaging lesson plans for all grade levels that are aligned with the standards. Assessments are also available.
National Geographic provides free maps, photos, videos and daily news stories, as well as articles and features about animals, the environment, cultures, history, world music, and travel.
This site will teach students full about startling photography and mind-expanding writing on space, the environment, animals, even world music.