Why is 0 not a number?

[ElfOnTheTopShelf]

Surely it is classed as a number, even if it is nothing?
I've tried to set a few online things up recently, and my password is never accepted because "it must contain a number". Yes... it does... 0

That's a classic fallacy though DeWe

Go on tell us at what step the fallacy lies

In fact that is why zero is not a number, and why the fallacy of 1=2 exists; there isn't any number that we can uniquely and unambiguously define the quotient 0/0 to be

Yes the babylonians introduced a figure for zero when they wanted to write things down for other people to look at. until then they had just left a space in the string of numbers but this could easily get missed when copied.

so 0 is only in existence to make the columns right in the hundreds tens and units questions we have all been forced to complete throughtout childhood :)

This is a fab thread :) Do I know any of you? We should have a regular nerdy thread

Ok: (I can't work out how to do the little number so a^2 is a squared, ie a x a)
step 1: Let's say a=b
step 2: x both sides by a so a^2 =ab
Step 3: + a2 to both sides so a2 + a2 = a2 + ab
Step 4: simplify 2a2 = a2 + ab
Step 5: - 2ab from both sides so 2a2 - 2ab = a2 + ab - 2ab
Step 6: Simplify 2a2 - 2ab = a2 - ab
Step 7: Simplify using brackets 2( a2 -ab) = a2 - ab which you can write as: 2(a2 -ab) = 1 (a2 -ab)
Step 8: Cancel both sides by the stuff in the brackets ie (a^2 - ab)
Hence 1 = 2
Remember having lots of fun at school with these tricks.

I think 0/0 tends to often be defined as 1 for convenience, although it may depend on the particular mathematical area you're looking at.

What about on scales such as temperature? 0 degrees c is a recognised value - it's one degree warmer than - 1 and one degree cooler than 1. It's not an absence of temperature.

Well, temperature is as you define it, it's relative. You could choose to define 0 as the freezing temperature of water, or the average temperature in London in Febuary or the boiling point of your mobile phone. And what's a degree? Why is it the amount of temperature it is? They could have decided there were 10 degrees between freezing and boiling point of water, or 27 or 1032 rather than the (easier to deal with) 100.
It's a man made concept that is defined rather than "is".

If you have trouble sleeping it's all here

www.scribd.com/doc/25060500/History-of-Zero

In computer programming, zero is definitely classed as a number. I've never come across a programming language that doesn't recognise 0 as a digit.

I agree with Thisisyesterday's DP - this is about crap website design rather than number theory.

in computers 0 represents off and 1 represents on so it doesn't really act as a number although it is there as a digit.

0 is an element of the set of Real (as opposed to imaginary) numbers.

0 is a placeholder.

I can assure you that 0 is a number.

It's definitely a Real number. Whether it's a Natural number is up for grabs.

It's a whole number but not a natural number.

If 0 is a number, then the rule of any number divided by itself =1 would apply shirley? Therefore 0/0=1. My head hurts now.

DH says it's because some computers see 0 and discount it - so if you need a password of 10 digits and one is 0, it eliminates that. I do not get this myself, seems stupid!

But I also know my parents' phone number, which is from out in the sticks so is one digit short, is only accepted in some computerized forms if you put a zero at the end - and apparently if you key this into your phone complete with zero it gets through, too.