whats the name of these toys?

okay so my cousin and i use to play with these little robots that had removable parts, like the arms legs and head. each part had a number on it and it was the "power" it had. say your robots arm had 500 and your enemies had 300 than you would win. we use to play for parts so that we could build the strongest robot. we use to buy them at toys-r-us. and we played them in elementary school 2001-2002. we've forgotten the name of these toys and cant find any information online. its been driving us crazy for like a year now, so i was hoping one of you could help. we're not even sure we were paying it right... thanks