Can 2+2 really = 5?

Question

everyoen at my school says that it can.
but i dont belive them.
so im wondering?
can it?

Answer 1

That is an advanced mathematics assumption. It can if you redefine addition and use the same sign +...
For example let # represent a sign of our new addition, and + be still the sign in the old one
If we define x#y to be x+y+1, and then rename # with +
than 2+2=2#2=2+2+1=5... So in that case the answer is yes.
But with addition as we know it, and study in school 2+2 can't be 5.

Answer 2

I think the joke youre refering to is "2 + 2 = 5 for large values of 2". Of course its a joke, and it is absurd. But the reason it is funny is several things...

1. its kinda a calculus joke, a pun on the way mathematicians talk about limits (for large values of x 1/x tends towards zero...)

2. it also hints on the fact that there is a difference between estimated calcuations and real calculations. For instance
2.4 + 2.4 = 4.8 (2.4 rounded is 2, 2+2 = 4, but 4.8 rounded is 5)..

3. If you find 2+2=5 somewhere, that may be a hint that you arent supposed to read it literally. Maybe 2 isnt really "2", (like in case 2.). It may have some meaning, but perhaps not even remotely what you think (think codes). It's a reminder that context means everything.

Answer 3

Depends on the type of math you are talking about. It can, but it is very hard to explain how, and it has to do with the complexity theory of mathematics. But the two basic tenets of the complexity theory is that all complex systems (like the weather, or animal socialogy, or the economy) are inherently unpredictable and eventually anyone who tries to predict the system will fail at least once. An addition to this is that it is necessary for a complex system to fail (like hurricanes in weather, fights breaking out among various animals/humans, or recessions/depressions in the economy) because that is how you know it is healthy. Small failures signify a working system. No failure means that eventually the system will have to collapse and be completely destroyed.

The other tenet though is that the unpredictability has an underlying predictable order and so it can still be prepared for. Generally the system works for a time and then fails. Attempts are made by humans to fix the system, and these attempts work for a time to stabilize the system, but it will fail again and in a much larger way.

And in these systems the 2+2=5 mentality (meaning that sometimes that equation is unpredictable and that while most of the time it equals 4, it will eventually fail in a large system and equal 5, or 3, or any other number.) If we continue with this, we basically know 2+2 will not always equal 4 (because we know the underlying system will fail) but we don't know whether it will equal 3 or 5 or any other number, just that it will equal another number sooner or later.

Sorry to talk so much, but it is a large subject to get across with a question so large as the one you asked.

Answer 4

If you want to reinvent math and create a whole new definition, sure - you can have 2+2 = 5, 6, 27, pi, whatever you want. Make it up - it's fun.

But if you want to stay in the realm of "math", 2+2 will never equal 5 - not in calculus, not in complex theory, not in manifolds and modular forms, not in any type of mathematics people actualy use here on Earth.

Answer 5

Funny thing, that integer math. 2.4 + 2.4 = 4.8. But if you were to round all these numbers, you'd get 2 + 2 = 5. Oops! We have a rounding error!

Unless you're a computer programmer, or you're just into that kind of trivia, I wouldn't worry about it very much. All you really need to know is 2 + 2 = 4.

Answer 6

Yes, it can ... read my answer carefully

4 - 10 = 9 - 15
4 - 10 + 25/4 = 9 -15 + 25/4 [add 25/4 both sides]
(2 - 5/2) * (2 - 5/2) = (3 - 5/2) * (3 - 5/2)
2 - 5/2 = 3 - 5/2 [take square roots]
2 = 3 ......... [eqn. (i)]

Now, 2 + 2
=> 2 + 3 [replacing latter '2' by '3' from eqn.(i)]
=> 5
So, 2 + 2 = 5


[Fallacy : The negative nos. such that (2 - 5/2) have no simple square roots].
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By the way, I've read ur profile 'n hv loved ur "note to self". It's real...

Answer 7

A neurotic knows that 2 + 2 = 4 but does'nt like it.

Answer 8

Unless you're Winston in 1984 and the Party tells you that 2+2=5... the answer is four. :)

Answer 9

If you're using it to make an illogical statement, then yes.
In reality, 2+2=4.

Answer 10

if its 2 1/2 +2 1/2 or 10 / 0.5 but that totally different math.......usally 2+2=4