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Addition Facts


Date: Thu, 29 Jun 1995 00:23:23 +0300
From: Anonymous
Subject: adding 2 numbers

Hello,

I'd like to understand the reason for the 'fact' that 2+2 = 4.
(It's not a joke, it really interests me to understand this.)


Date: 5 Jul 1995 10:15:17 -0400
From: Dr. Ethan
Subject: Re: adding 2 numbers

Hey,
        
Well this problem is as much philosophical as it is mathematical.
The easiest (and somehow least satisfying) way to answer you is to say 
that it is definitional that 1+1 = 2 and that n + 1 = the next number bigger 
than n.

So 2+2 is 2+1+1, which is 3+1, which is 4.  The other way to think about it
is that + signifies the combining of two quantities, and the name for the
quantity that is the same size as 2 combined with itself is 4.

It really does come down to the "fact" that that is the definition.

If your question is more about why + was chosen to represent this combining
operation, write back and I will help you out.

Ethan Doctor On Call
    
Associated Topics:
Middle School Number Sense/About Numbers

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