From: Kelly Wheeler <the5@pacbell.net>
To: Teacher2Teacher Public Discussion
Date: 2003073022:03:10
Subject: Re: Front End Estimation

  Estimation is different from Rounding due to the fact that Rounding
compensates for the next smaller Significant Digit whereas Estimation
doesn't.

  This means that Estimation can be performed more quickly.  It can
also be implemented in systems that don't have access to the
subsequent digits (speaking of digital circuits).

  In your 4th grader's situation: 345+556 would, by FEE, be 
300 + 500 = 800
 or 
340 + 550 = 890

  The resolution is always an issue in all estimations.  Example:  I
have two cups of ingredients to mix.  Do I need a quart or gallon
container?  The resolution would be cups.  However, if I only have a
half a quart container or less, I should estimate the cups of
ingredients.  Are they full cups or half cups?

  The resolution needed is absolutely necessary in these equations and
are far too often forgotten by teachers (and therefore their
students).  This leads to incorrect answers and frustrated students
(and parents).

Kelly

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