Math Websites:
Number and Operations: http://www.internet4classrooms.com/grade_level_help/skills_fourth_4th_math_number_and_operations.htm
Algebra: http://www.internet4classrooms.com/grade_level_help/skills_fourth_4th_math_algebra.htm
Geometry: http://www.internet4classrooms.com/grade_level_help/skills_fourth_4th_math_geometry.htm
Measurement: http://www.internet4classrooms.com/grade_level_help/skills_fourth_4th_math_measurement.htm
Data Analysis and Probability: http://www.internet4classrooms.com/grade_level_help/skills_fourth_4th_math_data_analysis_and_probability.htm
Reading Websites:
Comic Creator: http://www.readwritethink.org/files/resources/interactives/comic/index.html
Kid's Mysteries: http://kids.mysterynet.com/
Mad Libs: http://www.funbrain.com/brain/ReadingBrain/ReadingBrain.html
Storyline Online: http://storylineonline.net/
Science Websites:
Life Science: http://www.internet4classrooms.com/skills_4th_science.htm#life
Earth Science: http://www.internet4classrooms.com/skills_4th_science.htm#earth
Physical Science: http://www.internet4classrooms.com/skills_4th_science.htm#physical
Misc. Website:
Time For Kids: http://www.timeforkids.com/TFK/index.html
Catch The Spelling: http://www.manythings.org/cts/