# Why does 2+2=4? **URL:** \ **Category:** Factual Questions\ **Created:** [February 2, 2004, 12:41pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180 "2004-02-02T12:41:31Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Airman\_Doors\_USAF](https://avatars.discourse-cdn.com/v4/letter/a/e36b37/32.png) [@Airman\_Doors\_USAF](https://boards.straightdope.com/u/Airman_Doors_USAF)\ **Post date:** [February 2, 2004, 5:27pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/21 "2004-02-02T17:27:17Z")
Excuse me. I was being silly. Nonetheless, there is some truth to it, but I guess it doesn’t fit in to the discussion. Sorry for the interruption. ---
**Author:** ![Ramanujan](https://avatars.discourse-cdn.com/v4/letter/r/51bf81/32.png) [@Ramanujan](https://boards.straightdope.com/u/Ramanujan)\ **Post date:** [February 2, 2004, 6:17pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/22 "2004-02-02T18:17:11Z")
> [@jovan](#): > > I don’t believe this statement is true. Mathematics can be _used_ to describe the real world, but pure math is completely separate and independant from materiality. i have to disagree with you here. nothing is independent of materiality. the principle of noncontradiction, for example, could just be “not so” in a different sort of universe. that we can’t speak meaningfully of such a universe does not mean that no such universe is possible. this is simply how our universe operates, and we do our best to describe it. ---
**Author:** ![AtomicDog](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@AtomicDog](https://boards.straightdope.com/u/AtomicDog)\ **Post date:** [February 2, 2004, 9:28pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/23 "2004-02-02T21:28:33Z")
> [@Airman Doors](#): > > Excuse me. I was being silly. [British General] Stop it.[/British General] ---
**Author:** ![Lawn\_Mower](https://avatars.discourse-cdn.com/v4/letter/l/8dc957/32.png) [@Lawn\_Mower](https://boards.straightdope.com/u/Lawn_Mower)\ **Post date:** [February 2, 2004, 11:03pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/24 "2004-02-02T23:03:45Z")
Keep it simple… take 2 Apples add 2 more how many do you have? 4! :eek: ---
**Author:** ![Bippy\_the\_Beardless](https://avatars.discourse-cdn.com/v4/letter/b/ac8455/32.png) [@Bippy\_the\_Beardless](https://boards.straightdope.com/u/Bippy_the_Beardless)\ **Post date:** [February 2, 2004, 11:18pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/25 "2004-02-02T23:18:05Z")
I think the maths of this problem has been thoughly covered, so I would like to take a moment to consider the language of this problem. The = sign gets translated into several different words. (+ sign similarly has various wordings, some I use below, but none are problamatic, unlike the synonyms for the = sign.) equals : Good word, but doesn’t really give the meaning of the sign just the name of it becomes : This is sometimes used, but is bad, this leads to the (Platonic I think) conjecture that “How comes 2 and 2 becomes 4, what is this and (plus) such that somehow things have changed from 2 + 2 into 4?” is the same as : This is a long old phraise, but it gets to the heart of the matter. 2 plus 2 is the same as 4, there is no sence of change from one state to the other, both states are the same. Unfortunately, computing has taken the ‘becomes’ meaning and has run with it giving us coding structures such as x=x+1 just to add to confusion of the = sign. ---
**Author:** ![Achernar](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@Achernar](https://boards.straightdope.com/u/Achernar)\ **Post date:** [February 2, 2004, 11:59pm UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/26 "2004-02-02T23:59:17Z")
When we say x = y, we mean that every property that x has, y also has, and every property that y has, x also has. I don’t think anyone is really confused by the used of = as assignment operator in programming. ---
**Author:** ![bonzer](https://avatars.discourse-cdn.com/v4/letter/b/45deac/32.png) [@bonzer](https://boards.straightdope.com/u/bonzer)\ **Post date:** [February 3, 2004, 12:22am UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/27 "2004-02-03T00:22:54Z")
> [@Achernar](#): > > Actually, while it is hundreds of pages into _Principia Mathematica_ that they get to 1+1=2, I think they could have done it much faster, but that wasn’t the point of the book. They were trying to codify all of mathematics from the ground up; 1+1=2 was just a tangent they spent a page on. Agreed. Though the myth that the book is about 1+1=2 has surely been given legs by the fact that the CUP’s standard abridgement \*Principia Mathematica to _56_, in print since 1962, more or less culminates with \*54.43. From that, there’s only about 20 pages to the end of the main text. While Whitehead was dead, the abridgement was presumably approved by Russell. [Though about a quarter of the abridgement is the original introduction, which had mainly been written by Russell and which is a brilliant example of his skill at technical exposition. So he may have been biased in agreeing what to include.] ---
**Author:** ![Russ1978](https://avatars.discourse-cdn.com/v4/letter/r/5e9695/32.png) [@Russ1978](https://boards.straightdope.com/u/Russ1978)\ **Post date:** [February 3, 2004, 12:29am UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/28 "2004-02-03T00:29:32Z")
Why is there 10 basic numbers?? ---
**Author:** ![GorillaMan](https://avatars.discourse-cdn.com/v4/letter/g/50afbb/32.png) [@GorillaMan](https://boards.straightdope.com/u/GorillaMan)\ **Post date:** [February 3, 2004, 12:38am UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/29 "2004-02-03T00:38:15Z")
> [@Russ1978](#): > > Why is there 10 basic numbers?? Because we have ten digits on our hands. It’s not as stupid an answer as it seems…there had to be _something_ as the base, and ideally something not tiny, and not massive. It was fairly predictable that the ‘winner’ would be the one which corresponded with what we reach when we count on our fingers. However, IIRC, not all societies have always used Base 10…was it the Greeks who used Base 60, hence our division of the hour into sixty minutes? Somebody who knows what they’re talking about can take over… ---
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [February 3, 2004, 3:10am UTC](https://boards.straightdope.com/t/why-does-2-2-4/227180/30 "2004-02-03T03:10:08Z")
It was the Babylonians that used the sexagismal (base 60) system. One thing I’m not clear about - nowadays, we’ve formalized the natural numbers using Peano’s axioms. It’s presented as if that’s how we started, historically; but of course we knew that 2+2=4 way before Peano was even born. Upon what we were basing that? [Previous page](https://boards.straightdope.com/t/why-does-2-2-4/227180.md?page=1)