on conception, we start to count the age of a fetus from zero (0) to whenever the baby arrives, and then start from zero. we never count down from 36 – 0 months, then take off when the bundle(s) arrive(s). when we die, we return to zero, but you hear people say, “he/she has been dead three years.” what life do they count after death – that of the soul? if body and soul make the living, (or dead as in this case), why not continue counting the age of the person. why go back to zero? is zero even necessary? why is zero even a number? forget about the explanations for how the qwerty keyboard was first laid out, why put 0 after 9? is zero an odd or even number? if it is, what does that make 0.5? those who argue whether zero is an odd or even ‘number’ use the parity argument.  they state that every even integer is immediately preceded and followed by an odd number (…, odd, even, odd, …).  then they expect me to believe, like in the case of the fetus, that it is clear that zero must be even because …,−1, 0, 1, …, −1, 0,1, shows that -1 comes before zero. what happened after 9? is there a numerical chasm that follows 9 before we start to count afresh? how do we get to -1 after 9? i have heard it argued, zero after any other number is even because it can be divided by 2. that zero fits the definition of “even number” because it is an integer multiple of 2, namely 0 × 2. in fact, there is an argument that zero is the most even number of all. then they argue that oddness/eveness/parity depends on how numbers interact with each other – how they multiply and add. now imagine this: even+even = even; odd+odd = even; even+odd = odd; even*odd = even; odd*odd = odd; and even*even = even. now, if we take the traditional real-number arithmetic (addition and multiplication) into consideration, then we’ll see that 0.5 poses some real issues. let’s assume, for the sake of mathematical completeness, that there has to be at least one even and one odd number in this abstract definition. then 0.5+0.5 = 1, which is odd.* so if 0.5 was either odd or even, it would break the defining rules above since its sum with itself is odd. but, my reasoning tells me, it is neither.