Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!hao!oddjob!gargoyle!ihnp4!homxb!whuts!spf
From: spf@whuts.UUCP (FRYSINGER)
Newsgroups: comp.edu
Subject: Re: Mental arithmetic, was: Calculators in exams, was: Becoming CAI literate
Message-ID: <3849@whuts.UUCP>
Date: 1 Mar 88 14:56:02 GMT
References: <2032@ukecc.engr.uky.edu> <3900008@nucsrl.UUCP> <24954@cca.CCA.COM> <1988Feb28.224421.6922@jarvis.csri.toronto.edu>
Distribution: na
Organization: AT&T Bell Laboratories
Lines: 30
Summary: Still has value

In article <1988Feb28.224421.6922@jarvis.csri.toronto.edu>, tjhorton@ai.toronto.edu.UUCP writes:
> I don't think mental arithmetic is very important for strong mathematical
> facility.  'Amusing oneself and startling others' may be important for TV
> game shows, but how much else?
> ... every student in the world capable
> of pressing buttons would surpass the accomplishments of Einstein, given
> enough 9 volt batteries.  Understanding arithmetic is important, but I
> question the value of the hours that would be needed to teach QUICK, MENTAL
> arithmetic in schools, when some much else of value is 'out there' in math
> to be learned.

Well, I think you've hit the nail on the head.  Yes, in most
situations calculators improve performance (speed & accuracy).
Unless you don't have one handy.  Or it's broken.

The ability (and willingness) to do mental arithmetic is certainly an
advantage when no calculator is around, as happens with me often.  I
even carry a calculator in my "go to work" shirt pocket, and still
frequently find myself in arithmetic situations without one.
Furthermore, if one loses the ability (or confidence, or willingness)
to DO mental arithmetic, how will one recognize (A) when your
calculator or your fingers have made a mistake, or (B) when someone
else or their calculator (e.g. a cashier) has goofed?

Since proper training to do mental arithmetic is in fact a very minor
effort (mostly done by parents, not teachers), it's well worth doing.

Steve Frysinger

P.S. By the way, the same goes for doing arithmetic long hand.  When's
the last time you balanced your checkbook by hand?