What Does a Vertical Bar Mean?

Date: 01/29/2001 at 19:33:16
From: Kyle
Subject: Wondering what the |'s mean

I saw the |'s on the ACT exam, and coudn't figure out what they meant. 
I'm not a senior; I'm taking the ACT in 7th grade to send to colleges 
in advance, and since I never took any classes discussing this symbol, 
I was curious. I want to know what the symbol | means, for example 
|2+3| . Just wondering. 

Thanks, Dr. Math.

Date: 01/29/2001 at 19:37:56
From: Doctor Schwa
Subject: Re: Wondering what the |'s mean

It means "absolute value," or, in other words, "distance from 0 on the 
number line."

That is, |3| = 3, and |-3| = 3 also, because they are both 3 units
away from 0.

- Doctor Schwa, The Math Forum
  http://mathforum.org/dr.math/