# When does 1+1=3? [closed]

When does one plus one equal three?

• According to an old joke, this is true for extremely large values of 1 – Julian Rosen Nov 27 '14 at 19:24
• According to an M&A joke, this is the definition of 'synergies'. – A E Nov 27 '14 at 20:17
• With Banach-Tarsky, 1+0=2. Should be easy from there... – Cephalopod Nov 27 '14 at 20:25
• 1+1 => 11 => 11 in binary is 3 in decimal. – stackErr Nov 28 '14 at 18:17
• – nicael Nov 30 '14 at 17:21

The following slightly abuses the notion of "equals" but in a way that is common among non-mathematicians (more or less "And the next thing we get is...")

When a woman plus a man gives a woman plus a child plus a man.

• This was the answer I had in mind. – josh Nov 27 '14 at 20:49

I have a mathematical proof for you:

Start with the following simple equation: $$a = b$$ (step 1) Multiply both sides by $b$: $$ab = b^2$$ (step 2) Subtract $a^2$ from both sides and factorize: $$ab - a^2 = b^2 - a^2$$ (step 3) $$a(b-a) = (b+a)(b-a)$$ (step 4) Simplify and add 1 to both sides: $$a = b + a$$ (step 5) $$a + 1 = b + a + 1$$ Now since $a = b$ (the starting point of this proof), we can write this as: $$a + 1 = 2a + 1$$ And in the case where $a = 1$, we have: $$1 + 1 = 2 + 1$$ So, therefore, $$1 + 1 = 3$$

• Bonus to viewers, can you spot his mistake? XD – warspyking Nov 27 '14 at 20:11
• i1.kym-cdn.com/photos/images/newsfeed/000/005/378/zero.jpg – A E Nov 27 '14 at 20:12
• you can't divide by 0 – MihaiC Nov 28 '14 at 10:33
• I like how you divide by (a-b), but deliberately gloss over it by not writing a comment saying what you're doing like you do for all the other steps. – Kevin Nov 30 '14 at 7:42
• One of my teachers once told me that you can prove anything if you divide by zero. – Allan Apr 13 '15 at 22:42

When? This is very easy...

Never.

Here is an image that shows that 1 + 1 = 3:

1+1=3 When

the one who calculated it doesn't know maths or not good in maths (probably a small child or someone who doesn't learned mathematics properly)

Well, 1 + 1 has always equaled 3 :D

You see long ago, when the very first few math geniuses got together to come up with basic rules, they gave it lots of thought and settled on what's taught today.

But you see, numbers don't truly exist, they're a concept created by the human mind, and because our mind has created and developed them for years, and they are all in our head, we can merely change them.

So if you think 1 + 1 = 3, who cares if teachers and professionals say you're wrong! You are correct! Never forget that kids ;D Don't stop imagining! :D