Mr. Reimer on Calculators:  

The Good, The Bad & The Ugly

The Good:                               

Calculators are a fantastic invention.  Why?  One reason alone:  they are fast.  I mean they are really, really, really fast.  Speed is cool.  Speed is powerful.  Speed is good. 

The Bad:

Calculators are not magical demigods sent to provide us answers.  Calculators are tools.  You are the user of the tool.  You are in control of the calculator.  You are responsible for the answer that the calculator gives you.  Students who misuse calculators do so because they treat them as crutches, not as tools.  Here are just some of the reasons you must be careful.

• Calculators are dumb as dirt.  They give you the answer to the question you ask.  If you ask the wrong question, you got the right answer to your question, but you are at fault for asking the wrong question. 
• You must be able to check the reasonability of your answer.  If you don't know the math, you cannot do that.  We all have fat fingers and sometimes do the following:  hit the wrong key, forget to set the mode, do not use the appropriate window, incorrectly interpret the answer given.  You should be able to tell if your answer makes sense or not.  If it doesn't you need to ask the calculator the correct question.
• Your calculator sometimes only gives you one answer, when actually there are several.  You must know the math and how to use the calculator to take the further steps in finding all answers.
• Calculators provide an estimate.  When you are working with repeating decimals or irrational numbers, can you convert back?
• Calculators do not leave a "paper trail".  It is harder to check your work, unless you write down your steps. 
• Calculators are only one of the tools we have at our disposal.  Remember to use the best tool or technique for your problem.  If you only use a single tool, it is kind of like trying to do all woodworking with a hammer.  It is a good tool, but not as good as a saw for cutting.

The Ugly:

Any monkey can be taught to push buttons without knowing what he is doing.   You are smarter than a monkey.  Your brain is your best tool.

Here are a few reasons you should be able to do simple calculations in your head.

• You will not always have a calculator with you. 
• You will look ignorant if you need to take out a calculator to a simple calculation.  You will be diminished in their eyes.  They will think less of you.  If you do this in front of your boss she may be less likely to promote you, give you interesting assignments, offer you opportunities.  In general people will trust you less and they will think you are not as capable.
• You will not be able to check the reasonableness of your answers and you will then make more mistakes.  You will get lower grades.
• You need to be able to demonstrate your ability in understanding certain basic math concepts (e.g. fractions, decimals, rational number arithmetic ...)  Pushing buttons does not show this.
• You will find some more advanced math concepts harder to master (rational expressions, factoring...)
• Some calculations are just easier AND faster than the time it takes to get out your calculator and punch in the values.

Work Smart, Not Hard.  Learn the Basics.  Then use your calculator for its advantages!