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### Don't Use Calculators

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Date: 12/18/2000 at 18:09:30
From: donnamorris
Subject: Why should you not use calculators to do math?

Why should children not use calculators to do math? Please state
several reasons.

Thank you.
Ms. Morris
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Date: 12/18/2000 at 18:49:16
From: Doctor Ian
Subject: Re: Why should you not use calculators to do math?

Hi Ms. Morris,

It might be going a little too far to say that children "should not
use calculators" to do math. There are times when a calculator is just
the ticket - for example, when you want an approximate value for the
cube root of 59.

What children shouldn't do is _depend_ on calculators to do simple
calculations, like multiplying integers from 1 to 10, or adding and
subtracting numbers, or dividing numbers with relatively few digits.

(I wouldn't hesitate to whip out a calculator to compute something
like 2944521.324562 divided by 192.87465, although I might just divide
3 million by 200 and call it close enough for government work.)

Some reasons children shouldn't depend on calculators include:

1. There won't always be a calculator around when you need one; or if
there is one, the battery may be dead.

2. It's about a zillion times quicker to use your brain to figure out
that 7 x 6 = 42 than it is to key it into a calculator. This
doesn't make much difference if you just want to do one
calculation, but when you're simplifying algebraic expressions you
typically do dozens, even hundreds of simple calculations, which
makes relying on a calculator sort of like trying to run a marathon
and having to stop every twenty feet to re-tie your shoes.

3. Calculators only use decimal approximations to real numbers, which
gives an unrealistic idea of how the real number system works, and
obliterates any opportunity to develop an appreciation for the
crucial difference between an exact answer and an approximate one.

4. Children who depend on calculators without developing an
independent number sense are unable to tell when they've arrived
wrong number, or have missed a decimal point, or made some similar
error. So they can be computing the speed of a train, get an
answer like '394312353.31395 miles per hour', and have no choice
but to assume that it must be right, because it's 'what the
calculator said'.

5. Learning to get along without a calculator is an excellent object
lesson in growing up. The essence of becoming an adult is learning
to put up with a little pain up front in order to avoid a lot of
pain later on. Children who avoid the pain of learning their basic
arithmetic facts by depending on calculators are setting themselves
up for enormous amounts of pain and frustration later in life.

more, or if you have any other questions.

- Doctor Ian, The Math Forum
http://mathforum.org/dr.math/
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