Don't Use Calculators
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
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 at ridiculous answers because they've inadvertently typed in the 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. I hope this helps. Write back if you'd like to talk about this some more, or if you have any other questions. - Doctor Ian, The Math Forum http://mathforum.org/dr.math/
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