Fraction and decimals:
https://www.mrnussbaum.com/placevaluepirates/ (can be used for ordering decimals)
https://www.mathplayground.com/index_fractions.html
Multiplication practice websites:
www.multiplication.com
http://www.oswego.org/ocsd-web/games/SumSense/summulti.html
www.mathplayground.com
www.prodigy.com
Place Value:
https://www.mrnussbaum.com/placevaluepirates/