If you have two apples and I steal one then you eat the other how many apples do have left?
Basic arithmetic must be pretty convoluted in your world, let alone science.
I am thinking in terms of the Universe. 1 apple is a human name for a bunch of atoms tied together. 1.5 billion atoms - 1 billion atoms is 0.5 billion atoms. There is a lot of stuff left when you remove the apple. In science you will always have to be this specific. You can never let go of exactness. I have seen a few theories with 0 in them that fail. Also infinity is only possible for 1 case, and that is for the material that is outside of the universe... which I would just call an infinite membrane.