Parity of Zero - Why Zero Is Even

Why Zero Is Even

It is easy to directly prove that zero is even. A number is called even if it is an integer multiple of 2. As an example, the reason that 10 is even is that it equals 5 × 2. In the same way, zero is an integer multiple of 2, namely 0 × 2, so zero is even.

This proof starts with a standard definition of "even number". It is also possible to explain why zero is even without referring to formal definitions. The following explanations make sense of the idea that zero is even in terms of fundamental number concepts. From this foundation, one can provide a rationale for the definition itself—and its applicability to zero.