Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Education » math-teach

Topic: Changing Subtractions to Adding Negative Numbers
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  
MVTutor

Posts: 11
From: Mountain View, CA
Registered: 11/11/13
Changing Subtractions to Adding Negative Numbers
Posted: Nov 11, 2013 9:34 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hi,
In simplifying algebraic expressions, it seems convenient to change all subtractions to addition of the negative form of the terms. This enables the use of the associative and commutative properties of addition. For example,
2x-2-x-1 becomes 2x+(-2)+(-x)+(-1)
Then through commutation, I can get
2x+(-x)+(-2)+(-1)

Is this commonly done or do students have problems with this approach?

Can you suggest other methods?

Thanks, --John



Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.