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Topic: Re: el fractions etc (fwd)
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Karen Dee Michalowicz

Posts: 215
Registered: 12/4/04
Re: el fractions etc (fwd)
Posted: Aug 9, 1995 10:11 PM
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> According to Chih-Han sah:
> >
> >
> > Here is another explanation about the rule for division involving
> > fractions:
> >
> > One way to explain "what is a number (positive ones)?" is to
> > say that it is used to describe the "ratio" of "like quantities".
> >
> ><snip, snip>

> > Exercise: What is the average speed in mph of the ratio of a change
> > of 88 ft in distance to a change of 1 second in time?
> >
> >

I would be delighted if my fifth graders were at the
developmental level to really understand ratios, much less use them
in the explanation of division. However, I did like the
explanation and will save it for my math ed classes.

I do think Tad's explanation of division using unifix cubes is
understood by fifth graders. I use unifix cubes all the time.

Fifth graders are still very concrete in their thinking.
That's why a manipulative is essential to bridge that gap
between the concrete and abstract. And, we who are operating
at formal reasoning, must realize many of our students are not
even developmentally near this level.



Karen Dee

Math History Lives!

Karen Dee Michalowicz VQUEST Math Lead Teacher/Trainer
Upper School Mathematics Chair Virginia Quality Education
The Langley School in Sciences and Technology
1411 Balls Hill Rd, McLean, VA
22012 USA
703-356-1920(w) E-Mail:
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