https://www.internet4classrooms.com/grade_level_help.htm
This site is awesome! It has interactive websites grouped by grade level (K-8) and content area.
https://www.odysseyofthemind.com/
The Odyssey of the Mind site offers many ideas to foster creative thinking in your kids. Use “Practice Problems” and “Classroom Activities” sections.

https://www.hoagiesgifted.org/blog_hop_tolerance_equity.htm
This site provides information on the special needs of gifted youth, special programs available, and other topics in gifted education. Children will find contests, reading lists, and entertaining activities. This site has something for everyone
https://education.jlab.org/vocabhangman/
Science content vocabulary hangman
https://www.storylineonline.net/
Various books read by celebrities