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Topic: [math-learn] Transforming formulas
Replies: 55   Last Post: Feb 19, 2007 11:48 PM

 Messages: [ Previous | Next ]
 Chris Posts: 346 Registered: 12/4/04
Re: [math-learn] Transforming formulas
Posted: Jan 29, 2007 12:38 PM
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Antonija,

With my seventh-grade students, I would do transformations,
but, depending on context,
I would not necessarily expect them to be able to do it.

One time, in particular, that I recall using it is with the distance formula.

For whatever reason, there were many students who knew that r = D/t,
and when we started out with problems that required solving for D
there would immediately be questions, because their recollection of the formula
"didn't solve for" what they needed.

Other students could tell them that D = rt,
and I would always do the transformation for them,
to show them that the two formulas are "equivalent"
before I would show them how to solve the problem both ways.

I always found it fascinating that the students often had no problem
understanding how to solve the equation (once the values were plugged in),
but they were totally confused by the transformation, using the variables.

Chris

-----Original Message-----
From: ahorvatek@yahoo.com
To: math-learn@yahoogroups.com
Sent: Sun, 28 Jan 2007 10:55 AM
Subject: [math-learn] Transforming formulas

Hi!

In math and physics there are many formulas. Some of these formulas
are main formulas and other are derived.
For example,
formula A=a*b (for area of rectangle) is main formula and formulas
a=A/b and b=A/a are derived formulas.
Transforming of formula A=a*b into derivated formulas isn't so
complex, since formula A=a*b isn't complex.
But, we (in math and physics) have many formulas which are not
so "trivial". For example, formula for perimeter of rectangle is
P=2a+2b, area of triangle is A=a*h/2, area of trapezium is A=(a+c)
*h/2, etc. Transformations of such formulas are much complicated.

Do you teach your students how to transform formulas?
Do you teach it just for some special cases or more generally?
When (in which class, with which age of students)?

Antonija

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Date Subject Author
1/28/07 Antonija Horvatek
1/28/07 John Morse
1/28/07 Zeev Wurman
1/28/07 Ed Wall
1/28/07 Richard Sisley
1/29/07 Rex Boggs
1/29/07 Rex Boggs
1/29/07 John Morse
1/29/07 Chris
1/29/07 John Morse
1/29/07 Antonija Horvatek
1/29/07 John Clement
1/30/07 Paul A. Tanner III
1/30/07 Joshua Zucker
1/31/07 Paul A. Tanner III
1/31/07 Moti
1/31/07 Paul A. Tanner III
1/31/07 timotha@comcast.net
2/1/07 Moti
2/1/07 Antonija Horvatek
2/1/07 John Clement
2/2/07 timotha@comcast.net
2/2/07 John Clement
2/2/07 timotha@comcast.net
2/2/07 Moti
2/2/07 Paul A. Tanner III
2/3/07 Moti
2/3/07 John Clement
2/5/07 Moti
2/5/07 Ed Wall
2/8/07 John Morse
2/4/07 Paul A. Tanner III
2/5/07 Moti Levi
2/4/07 Antonija Horvatek
2/2/07 Ralph A. Raimi
2/3/07 Moti
2/3/07 Ralph A. Raimi
2/4/07 Moti
2/4/07 Ralph A. Raimi
2/5/07 Alva
2/5/07 Moti Levi
2/5/07 John Clement
2/5/07 Ed Wall
2/5/07 John Clement
2/5/07 Ed Wall
2/5/07 Moti
1/30/07 John Clement
1/31/07 Antonija Horvatek
1/31/07 Paul A. Tanner III
2/1/07 Moti
2/1/07 Antonija Horvatek
2/1/07 Antonija Horvatek
1/29/07 Paul A. Tanner III
1/30/07 Jerome Epstein
2/19/07 Jon Wilson
1/30/07 Jerome Epstein