$9 vs $90

(From May 2011)

In previous posts, I mention the pros and cons of a calculator. Obviously, every math student needs a calculator at some point. (Square roots, trig functions, and other complex calculations require a calculator---or a genius--- to get the exact answer... )...  So, which calculator is best?
While working with an algebra student in Highland Park, I realized that my $9 'cheapo' calculator was simpler (and more effective) than her brother's $90 advanced TI calculator. Why?  And, besides cost, is it preferable to use a less sophisticated, cheaper calculator?  (read more below)



We were doing very basic trig operations: sine, cosine, tangent. When she input the values to find the inverse tangent (arctangent), the output on her calculator was strange.. After a few minutes of trial and error, I realized that the calculator was in "radians" mode rather than "degrees" mode.. (Try explaining the difference to a young math student!)...  It took a moment to figure out how to switch modes and input the values into the programmable calculator...  In the meantime, she used my $9 calculator with simple trig functions to solve the other problems...
So, does that mean the $90 calculator is unnecessary? Of course not.. It is necessary for calculus and advanced college courses.. Also, it's a must for physics, engineering, or business classes...  But, just make sure the user understands all the keys, functions, and modes!  (If the functions don't make sense, it may be better to get a less sophisticated model----for a fraction of the price...)

NOTE: Of course, the modern graphing calculators will always offer more than a basic caculator...)