Each piece of the pie is one slice, put them together it's one pie. I'm no Catholic apologist, that's just how I've had it explained to me.
Catholics also use this one a lot..
“You’re dwelling on details”. These details seemed unimportant to him.
.. if you ask too many questions. I've always considered it a copout in the past.. but maybe they have a point. No one will be able to address all of the minutae related to their religion.