The first sentence "A (real or complex) number having the property that any number does not change if zero is added to it" seems insufficient to capture the notion. An article entitled simply "zero" should probably have some sort of historical introduction about the concept of zero, even though there is ample scope for an entire article on that subject alone.
Even taking the modern algebraic concept of a zero element, the article needs to separate out the concept of the identity element of an abelian group written additively, and the absorbing element of a semigroup written multiplicatively, as these are the two main generalisations of the properties of the real number zero. Richard Pinch (talk) 22:07, 27 December 2013 (CET)
Zero. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Zero&oldid=31214