Most schools I've heard of don't group for reading anymore either. I know ours doesn't.
As I understand it, grouping (teaching kids in groups of similar ability and/or achievement) got unfairly associated with tracking (once you're on this track you can't get off it) in the minds of many people, and it has lately been considered an elitist teaching strategy. As that's frowned upon, there's a lot less grouping than there used to be. It's a shame because it's one proven teaching strategy that allows kids of all ability levels to advance.
Count your lucky stars that you have grouping in reading! Maybe you can get them to apply that idea to math, too. More power to you!
(While you're at it, can you get reading groups back in my local school, please?)
