STEM works: Wide variety of STEM activities (stem-works.com/activities)
NASA Kid’s Club: https://www.nasa.gov/kidsclub/index.html#.VIWzXzHF-So
Exploratorium: https://www.exploratorium.edu/explore
Funology: https://www.funology.com/
Science Buddies: https://www.sciencebuddies.org/
Tynker: https://www.tynker.com/
Wonderville: https://wonderville.org/studentAudience
STEM BrainPop: https://www.brainpop.com/stem/
Hour of Code: https://hourofcode.com/us/learn
Coding: online tutorials and short courses to teach coding and computer science (code.org)
PBS Design Squad: A variety of activities that can be completed online or offline (https://pbskids.org/designsquad/build/)