I have not seen any Math manipulatives being used in my classroom. I am in an English classroom and that is probably the reason i haven't seen any math manipulatives. I think because its an english class students are focused more on reading and writing than on math. I would use math manipulatives in my future classroom because they are a very helpful  for when kids count and add. Manipulatives also allow for fun activities and cool stuff that you can play with.