IXL: https://www.ixl.com/
A+Math: aplusmath.com
Math Playground: http://www.mathplayground.com/
Starfall: http://www.starfall.com/
Sumdog: https://www.sumdog.com/
Scholastic Kids: https://www.scholastic.com/kids/home/
ABCYa: http://www.abcya.com/
National Geographic Kids: kids.nationalgeographic.com/
Time for Kids: https://www.timeforkids.com/
Wonderopolis: https://wonderopolis.org/
Dance Mat Typing: www.bbc.co.uk/guides/z3c6tfr