2 + 2 = 4,,,,, right?

Question

im sure there are some math theos out there that beg to differ.. tell me why,, im interested

I've heard some say otherwise and I really want to hear from them and let them explain why... thanks

Answer 1

It's not math, but 2+2=5 was an important topic in Orwell's 1984.

"He picked up the children's history book and looked at the
portrait of Big Brother which formed its frontispiece. The
hypnotic eyes gazed into his own. It was as though some huge
force were pressing down upon you -- something that penetrated
inside your skull, battering against your brain, frightening
you out of your beliefs, persuading you, almost, to deny the
evidence of your senses. In the end the Party would announce
that two and two made five, and you would have to believe it.
It was inevitable that they should make that claim sooner or
later: the logic of their position demanded it. Not merely the
validity of experience, but the very existence of external
reality, was tacitly denied by their philosophy. The heresy of
heresies was common sense. And what was terrifying was not that
they would kill you for thinking otherwise, but that they might
be right. For, after all, how do we know that two and two make
four? Or that the force of gravity works? Or that the past is
unchangeable? If both the past and the external world exist
only in the mind, and if the mind itself is controllable what
then?
But no! His courage seemed suddenly to stiffen of its own
accord. The face of O'Brien, not called up by any obvious
association, had floated into his mind. He knew, with more
certainty than before, that O'Brien was on his side. He was
writing the diary for O'Brien -- to O'Brien: it was like
an interminable letter which no one would ever read, but which
was addressed to a particular person and took its colour from
that fact.
The Party told you to reject the evidence of your eyes and
ears. It was their final, most essential command. His heart
sank as he thought of the enormous power arrayed against him,
the ease with which any Party intellectual would overthrow him
in debate, the subtle arguments which he would not be able to
understand, much less answer. And yet he was in the right! They
were wrong and he was right. The obvious, the silly, and the
true had got to be defended. Truisms are true, hold on to that!
The solid world exists, its laws do not change. Stones are
hard, water is wet, objects unsupported fall towards the
earth's centre. With the feeling that he was speaking to
O'Brien, and also that he was setting forth an important axiom,
he wrote:
Freedom is the freedom to say that two plus two make
four. If that is granted, all else follows."

Answer 2

It depends on what you mean by "2" and "4"...
In the standard real number system of course 2 + 2 = 4 is always true.

Let us look at integers in a different light...
Pick an integer m > 1. Then any integer n can be written uniquely as n = m * q + r with 0 <= r < m. ( Think of q as the quotient and r the remainder when dividing n by m. )

In such a case we say that n = r ( mod m ). Now, consider integers "equivalent" if they have the same remainder when divided by m. In this case we say that a = b ( mod m ) when a and b have the same remainder after division by m. We can then consider 0, 1, 2, ... , (m-1) as the "residue classes" obtained from the above equivalence.

( As an example, consider a clock. 14 o'clock would be 2 hours after 12 o'clock -> 2 o'clock. 20 o'clock is 8 hours after 12 o'clock -> 8 o'clock. So that 14 and 2 are equivalent, 20 and 8 are equivalent, ... This is the same as (mod 12) )

Addition is defined as in the clock example, by adding the numbers and then taking the remainder.
9 + 7 = 16 = 4 (mod 12)
8 + 17 = 25 = 1 (mod 12)

Now, what is so special about 12? What if we use a "clock" with only 5 hours?
2 + 4 = 6 = 1 (mod 5) because the remainder of 6, when divided by 5 is 1.

What if we use 4 hours, 3 hours, or 2 hours?
2 + 2 = 4 = 0 (mod 4)
2 + 2 = 4 = 1 (mod 3)
2 + 2 = 4 = 0 (mod 2)

Answer 3

Same as 2 x 2

Answer 4

No, 2+2 is 22!

Answer 5

I've seen many mathematical 'proofs' that 2 + 2 = 5 or some variance of this. All of them are making are same mistake of dividing with 0, which is commonly known to be an illegal operation in mathematics. It is probably one of these broken proofs that you've seen.

Answer 6

Here is one of the closest but doesn't really make sense to answer your negative answer.

2 + 2 = 4

but

2^x + 2^x not= 4^x

Answer 7

Yeah and 2 twice 1,2 +3,4 Now 4 is the answer

Answer 8

yeah but 3+1=4 also..

Answer 9

yes its questioned because mathmaticians like to stain their brain by making things harder than they are
if u have 2 and u add 2 by countin from zero it can be 5 (2 +0,1,2=5 )

Answer 10

Yes. But does it equal 5...?