The website I swear it was called was: FunMath and had a slogan of: “Where math comes to life.” Though when I search google, nothing comes up. I remember it from 2nd grade. Roughly around 2006-2009. To add more - the website did have a place to just do lessons for math online but it also had an online multiplayer section too. The math categories had three difficulties: Addition, Subtraction, and Multiplication (maybe division as well) When you clicked start you would be brought into a map where it would find players around the world and when it found it’s players it would zoom into them on the map and display their name. It’ll do this for every player before the game starts. The site also had a shop where you could customize your avatar with coins and such. It had moving backgrounds and I remember specifically that a bandana for the avatar shop was removed.