Equal Additions

Date: 11/01/97 at 19:07:59
From: Karl Gabzdyl
Subject: Equal Additions

Dear Dr. Math,

Could you please provide me information on the "Equal Additions" 
method for subtraction?  A trip to the library produced many 
interesting facts but did not tell us what this algorithms is.  
Can you help?  

The parent of a gifted 4th grader.

Karl A Gabzdyl

Date: 11/05/97 at 14:59:04
From: Doctor Terrel
Subject: Re: Equal Additions

Equal additions for subtracting goes like this:

    67  + 1  =  68
  - 49  + 1  =  50
 -----         ---
                18

You see, we converted a hard case involving "borrowing", into 
a case that had easier numbers. While the principle is easy and 
straightforward, to put it into practice may take some "practice".   
:)

-Doctor Terrel,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/