Love this website for quick worksheets to add a little more to my little girls curriculum. While we get enough with MFW she just loves to do worksheets! S is for Sun Worksheet - D'Nealian - Twisty Noodle
This place has some great science and history ideas for the third grade. These could be edited to work with a higher or lower grade. Third Grade Thinkers: Science: Earth Cycles Need to make sure its accurate to prevent misconceptions!