Monday, May 20, 2013

Parity of Zero

Did you know: As much as half the population doesn't know that zero is an even number? And that this can cause problems in cases like gas-rationing based on license plates' last digit (as happened here in NYC last fall after Hurricane Sandy).


  1. Numbers parity

    Any number, except zero, multiplied twice, is an even number.
    A pair has two elements.


    One multiplied twice, result is a pair.
    A pair has two elements.

    Two multiplied twice, result is two pairs.
    Zero exception:

    Zero multiplied twice, resulting zero pairs.
    Zero pair has zero elements, therefore:

    The number zero is neither odd nor even.


    The smallest odd number is one.
    The lowest even number is two.
    The number zero is neither odd nor even.

    The classic definition:

    necessary condition,
    to determine whether a number is even,
    to be divisible by two.

    Original link

    1. Ha, that's pretty lunatic. I'll leave it here for laughs.

      Of course, the key gap is to leave a blank where the definition should go. Math is always about starting with a careful definition.