
Re: Useful problems
Posted:
Jun 15, 1996 3:15 PM


Marge's post reminds me of some of my pet peeves, which came up a lot when I was working with 6th graders recently: Rulers (the garden variety you can get at the supermarket) come in inches and base 2 fractions: halves, fourths, eighths, etc. Calculators (the garden variety you can get at the supermarket) come only in decimals. Most kids have these sorts of tools: their parents are not going to look around for a fraction calculator, or a ruler in tenths of an inch. So to do length computations with these standard tools, you have to do lots of conversions back and forth. True, it's good exercise, but it's a real pain in the neck if you have to do more than a few.
Susan Addington until June 15, 1996: After June 15, 1996: addingto@geom.umn.edu susan@math.csusb.edu The Geometry Center Math Department 1300 South 2nd St., Suite 500 California State University Minneapolis, MN 55454 San Bernardino, CA 92407 (612) 6245058 (909) 8805362 fax: (612) 6267131 (fax) (909) 8807119 WWW at Geometry Center: http://www.geom.umn.edu/~addingto/ WWW at CSUSB: http://www.math.csusb.edu/faculty/susan/home.html ***** NEW MATH GAME! ****** Check my Web pages for The Number Bracelets Game.
On Sat, 15 Jun 1996 MCotton@aol.com wrote:
> In a message dated 960614 12:15:44 EDT, ach@tenet.edu (Arthur Howard) > writes: > > > For instance, in our decimal world, who actually > >needs to divide fractions, as fractions, and get a fractional answer? > > > > > > I believe that there are at least 2 or 3 very important reasons to teach > fractions. > 1) As a concrete basis for the algebraic manipulation of variables. > Multiplying by the reciprocal equals 1 > Multiplication by 1 leaves the original number unchanged > The need to find a common denominator when adding fractions. > How to simplify expressions by cancelling common factors in both > the numerator and the denominator. > 2) The construction trade in the United States is still firmly committed > to the footinch measurement system. Students need to be able to read > a ruler! > 3) Much of scientific information is written using variables, and left in > fractional form until the last step when numbers are substituted. > > Marge Cotton > mcotton@aol.com >

