Below you will find many websites that have Math content:
Fun Brain
Math Playground
Cool Math
IXL
Primary Games
Khan Academy
Gogo Math
Buzz Math
Mathway
Math Central
BrainPOP
Kahoot
Math Games
Hooda Math
Splash Learn
PBS Kids
Cool Kindergarten
Funterra
Summertime Spot the Shapes
Maths Zone
First in Math
Math Blaster
Turtle Diary
Bed Time Math