Pam
Posts:
1,507
Registered:
12/6/04


Re: Simplifying Algebraic Expressions with Subtracted Expressions
Posted:
Nov 17, 2013 7:42 PM


Posted: Nov 17, 2013 2:08 PM by Bob: > > Hold on! I resemble these remarks, that's my > approach!:)
No, that is the Singapore Primary Mathematics approach.
> > I didn't have a problem with diagraming as a way to > help students realize the mathematical context of the > problem. It was when you were using the bars as a > gimmick with which to compute fractions that I had a > problem. I said label the bars 3/5 and 1  3/5 (or > just 2/5) and let arithmetic and reasoning take its > course. You were dividing the bar into fifths and > then magically dividing those fifths into halves and > shading this piece here and that piece over there. > That was what I had a problem with. Yes, an > illustration, but not a solving strategy.
Why, oh why, would I not use the information given?? 3/5 is three fifths! "Magically"? There is no magic involved, simply an understanding of fractions!
> > > See? Simply algebra but without having to know how > to do algebraic manipulations with variable letters. > > I don't understand what you mean?
An algebra mirror then. The solution via bar diagrams mirrors the algebraic solution. Although, since in both we are manipulating unknowns, simply with different representations, I think algebra is not such a stretch.
Pam

