There are many strange and wonderful calculations around that will baffle you. Those that will baffle you the most are those that show that what you thought was a fact, is wrong. With numbers nothing is imposible. I tweeted about a few of these and they were well recieved, I have also collected some from there. @ianthomson and @mdreid were fantastic fun 
It all started with 2+2=5
A bit of history:
The bolbs were descendants of the incas and they figured that when a 2-knot rope is put together with another 2-knot rope, a 5-knot rope result.
Rumour has it that the Pythagorean Brotherhood discovered 2+2=5 but ran out of funds so it never got wrritten up!
Fermat had proof of the equation as well and it was in his book, however it was cut out by the editor so the book could have wider margins.
Apparently “Bishop Berkey” said “ ”Well, now I know where all the departed quantities went to — the right-hand side of this equation.” and because everyone thought this was so cool, they called the university after him.
Read more about the history of the equaiton here.
Anyway…This is why:
4 + 4 = 10base8 -> divide both sides of the equation by 2
or again:
Lemma: 0 = 1
As a consequence of the lemma: 2 + 2 = 2 + 2 + 0 = 2 + 2 + 1 = 5
And also:
2.4 + 2.4 = 4.8 – rounded up to the nearest whole we get 2+2=5
This is why we says that “2+2=5 for extremely large values of 2″
(There are many more ways of doing this)
Here are a few other examples:
we know that : 1/3 = 0.333…
If we multipy it by 3 we get
3/3 = 0.999…
Therefore 1 = 0.999… – 0.999…
0.000…1 = 0 / 0.000…1
1 = 0
a = b
a^2 = a*b
a^2 – b^2 = a*b – b^2
(a + b)(a – b) = b(a – b)
a + b = b
2b = b
2 = 1
x = y
x-y = 0
2x-2y = 0
x-y = 2x-2y
1(x-y) = 2(x-y)
1 = 2
By @mdreid
1 = sqrt{1} = sqrt{-1.-1} = sqrt{-1}.sqrt{-1} = -1
1! = 0!
1 = 0
Can you think of any others? This was the best fun. No? You didn’t like it?
Just in case someone wants to know how all these are possible… they are all based on a small mistake that’s more or less hard to notice.
for example:
it get’s from (a + b)(a – b) = b(a – b) to a + b = b … how? by dividing the equation with (a-b) the only thing is that since a=b a-b=0 and you can’t divide something with 0
Yep! No mention of that on purpose because I was waiting to see if anyone would volunteer it! You cannot divide by zero. But it is fun though. Actually can you prove you can?