Can decimals be odd or even?

I was just wondering if the normal rules for odd and even numbers could be applied or perhaps extended to included decimal numbers as well. I thought it would be something involving the denominator of the fraction e.g. 1.4=7/5 but this is just a guess and probably wrong

Thanks for the help

Short answer: no

Longer answer: 7/5 = 14/10 so would that be odd or even in your system?

Short answer: no

Longer answer: 7/5 = 14/10 so would that be odd or even in your system?

Well, that can still be reduced to the simpler terms of 7/5 so I am talking about the simplest form of the fraction , so it would be odd if this system is even right (it was just a guess anyway )

What about pi, or any irrational number (can't be expressed as a fraction)?

You could define rational numbers to be odd or even depending on the parity of their numorator when in their simplest form, but I don't think there is any sensible way to do it for irrationals.

EDIT: I suppose you extend it to at least algebraic numbers by making use of properties of their polynomial, but you would have to be carful with being consistent.

Yeah, I saw a link about this but I didn't get most of it so maybe it'll make more sense to you
http://math.stackexchange.com/questions/92451/can-decimal-numbers-be-considered-even-or-odd

How would you go about classing algebraic polynomials as odd or even?

That link is interesting, it gives the same definition I did of even/odd rationals but in a more complicated way (it goes much further though).

I suppose that for alegbraic numbers you could consider their integer polynomial of minimum degree with no common factors to all coefficiants (I think this is well defined i.e. there cannot be 2 such polynomials for 1 number), and then use the parity of that polynomial when evaluated at 0. This is consistent with the definition for rationals I gave.

I have no idea how to extend this to general real numbers, but I will have a think.

What about pi, or any irrational number (can't be expressed as a fraction)?

Nice to see that you understand it, but it's a bit too complex for me

So if I'm right, your method involves reducing a polynomial such as $x^3+2x+3$ to it's simplest form and the substituting 0 in as the value of x and evaluating the parity of this result, which in this case would be odd.

Seems alright to me, but there may be other ways which don't place as much importance on the constant term which seems to me to be the main focus of your method (that is if I even understand it properly )

That's effectively what I am saying, the parity of teh constant term is what matters. The problem with considering anything else is that with an integer. say a, the polynomial for that number is $x-a$, and we need the parity of a to be consistent with the parity deduced for the polynomial. There may be a more interesting method that doesn't have this problem though, and I don't really see anything interesting about the constant term of an algebraic numbers polynomial.

Is it not possible to express pi as pi²/pi ?