The value of 0/1 = 0

i.e. if we divide 0 by any number (except 0), then we always get 0 as a result.

Again, (0/0) or (any number/0) is not defined because we can not predict its value. 

So, division by zero is not defined.

If you look at the natural numbers, how much ever big the number is, you can still add a one and get a bigger number.

There is no end to it and that is when something becomes infinite, but it is still measurable and something even bigger or smaller still exists.

So, the number of positive integers is infinite.