
Re: Simplifying Algebraic Expressions with Subtracted Expressions
Posted:
Nov 14, 2013 9:05 PM



On Nov 14, 2013, at 7:48 PM, Joe Niederberger <niederberger@comcast.net> wrote:
> Well, your distinction is crisp enough, and useful. However it sheds no light on the origin of Ma's expression. Is she claiming most students would write down her one liner and proceed to simplify just by thinking about the word problem? If they (generally) would do so, some summary and explanation of their thoughts would be nice, though I realize that wasn't really the point of the paper.
When you see "Ted makes $30 an hour and needs to $300 for to fix his car. How many hours must Ted work?"
Do you think ...
(A) "300 / 30"
(B) "30 * X = 300, x = 300 / 30"
Elementary students, prior to algebra, do (A). They can't do (B), they don't know algebra. There aren't "steps". I can't believe now I am the one arguing against steps.:)
Bob Hansen

